(FORTUNE Magazine) – These are interesting times. And no, we don't consider that a curse. The business world that FORTUNE writes about has in recent years become strikingly less stodgy, less predictable, and more replete with compelling characters--not to mention billionaires. We're counting on the coming year to be another humdinger. What follows is an entirely unscientific list of business people we deem especially worthy of your attention.

JEFF BEZOS

For Web golden boy Jeff Bezos (1), 2000 is crunch time. The Amazon.com CEO is facing the most critical year of his company's short life. In 1999, Bezos made headlines by spending more than $800 million transforming his online bookseller into an e-commerce empire. If all goes according to plan, Amazon--which now offers everything from DVD players to bongo drums--will be the gateway to retailing on the Web. But can he really pull such a vast and ambitious operation together? And, more important, will he ever get it to turn a profit? During the Christmas season, the buzz surrounding Bezos' plans stirred up expectations: Amazon's stock price climbed 70% in the last three months of 1999. But in the year ahead, Bezos will finally have to prove that his company is running on more than just buzz.

MIKE ARMSTRONG

When Mike Armstrong (2) took over AT&T two years ago, Wall Street hailed the Harley-riding grandpa. The outsider foresaw what many AT&T insiders didn't: the emergence of broadband. Two years later, AT&T looks a lot different but not much healthier. Investors, wary of AT&T's $110 billion cable bet, sent the stock down about 15% from its February high. And Armstrong has only started spending. He'll shell out billions more retrofitting his new cable lines to carry phone calls. Even then, he won't have a direct line into most U.S. homes. This is the year Armstrong shapes his legacy--either as a visionary or a failed profligate. How will he do? Watch the numbers. (For more on this, see "AT&T's Big Bet Keeps Getting Dicier.")

JILL BARAD

She's like Combat Barbie: riddled with bullet holes and still standing. A year ago, Mattel CEO Jill Barad (3) missed revenue targets by $500 million--and then, deflecting the blame, forced out her No. 2. In October she missed big again, citing problems with a software acquisition, the Learning Co.--and the guys in charge got pushed out. Next to leave, say people close to Mattel: CFO Harry Pearce. With the stock off 72% from its 1998 high, how does the intense, self-protective Barad hang on? Mattel's passive board of directors, stacked with Barad cronies, stands by her. But clearly the board is growing less patient. Even if she makes Wall Street's lowered expectations this Christmas, she faces a big challenge in filling her depleted senior management. Headhunters say many candidates simply won't go to Mattel because they don't want to work for Barad.

JEFFREY IMMELT

Being Jeffrey Immelt must be tough just now. The whole world expects him to win the hottest CEO succession race of the decade, maybe of the century, following Jack Welch as General Electric's chief in April 2001. And for good reason: Immelt, 43, has 20 working years ahead of him and has performed terrifically running a big, high-tech manufacturing business (GE Medical Systems). But, of course, as the front-runner he can't say a word about it. (Nor will GE comment.) So in 2000 watch for movement of any kind involving Immelt or the other leading candidates, Power Systems head Robert Nardelli and Aircraft Engines chief James McNerney. Look for an announcement around midyear. If it gets to be September with no winner named, all bets are off.

MICHAEL EISNER/STEVE JOBS

In the beginning, Walt Disney gave the world the Mouse. A half-century later, Steve Jobs (5) introduced the world to the mouse with Apple's Macintosh computer. Could it be destiny? Here's the scenario currently being floated in both Silicon Valley and Hollywood: Pixar (which, like Apple, is headed by Jobs) and Walt Disney Co. have a huge hit on their hands in Toy Story 2. But Pixar's stock has been going nowhere, and neither has Disney's. Meanwhile, a constant rap on Disney CEO Michael Eisner (4) is that the man who brought the Mouse back from the dead in the 1980s can't seem to line up a suitable successor. So, this corporate screenplay goes, Jobs--fresh off his miraculous revitalization of Apple--could sell Pixar to Disney and become Eisner's heir apparent. Sure, there are problems with this swell plan, mainly that for both Eisner and Jobs, power sharing is a foreign concept. But it's fun to contemplate. Besides, Jobs is only interim CEO of Apple.

DAVID KOMANSKY

He's a big man with a big job--steering supertanker Merrill Lynch into the main current of e-commerce. He's only got 14,000 brokers and 85 years of company history pulling him the other way. But if Merrill is to retain or, some say, regain, its role as America's stock brokerage, CEO Komansky must be nimble and he must be quick. At least Komansky has made a start. After watching online upstarts like E*Trade, Ameritrade, and Schwab (especially Schwab) nibble and gnaw at Merrill's market share, Komansky & Co. rolled out $29.95 online trades in early December. The next 12 months will be critical. How many current customers will switch over? How many new customers will sign up? How many brokers will quit? And most important, how will this impact the bottom line? (Hint: Going from charging customers hundreds of dollars a trade to $29.95 calls for new math.)

JOHN REED/ROBERT RUBIN/SANDY WEILL

A company run by an odd couple of strong-minded CEOs and a third fellow accustomed to throwing around power globally sounds as if it would be a chaotic management mess. But former Treasury Secretary Robert Rubin's high-profile move into the Office of the Chairman at Citigroup, the world's largest financial company, just may be easing Citi's way into a new millennium. One well-informed insider says Rubin, 61, is skillfully helping co-CEOs John Reed, 60, and Sanford Weill, 66--at one time not communicating too well--arrive at decisions, many hashed out at a weekly meeting that the three hold. Each member of the troika has a specialty. Weill is the operator, and Reed is the visionary about the Internet and technology. Rubin has been mulling long-term strategy. Analytical in style, Rubin does his learning about Citi's businesses by asking questions and taking notes on a yellow pad. Turns out that's catching: Weill, by nature an intuitive, seat-of-the-pants manager, has amazed Citi insiders by himself beginning to scribble on a yellow pad. Don't think of Rubin as an in-the-wings CEO. When he was feeling out the job market, he told friends he didn't want to be a corporate boss.

BILL FORD JR.

The first family member to head Ford Motor since Henry II retired in 1980, William Clay Ford Jr. has been on the job as chairman for a year now, and he's ready to assume a higher profile. Job No. 1 is keeping energetic CEO Jacques Nasser happy and working with Nasser to broaden Ford's base from autos to other kinds of consumer products like Internet services. That won't be easy--Ford gets nearly 30% of its profits from the sale of big sport utilities alone--but Billy and Jac have $25.7 billion in cash to play with. Ford should outearn GM again in 1999 with another year of blowout profits, but it will have a tougher time in 2000. Sales in the all-important North American market will likely be weaker, and Ford will have to do better in Europe and South America to make up the difference.

MARY MEEKER

She's more than just the cornerstone of Morgan Stanley Dean Witter's Silicon Valley investment banking business, although that's why she was just paid a reported $15 million bonus. Internet analyst Mary Meeker (pictured) is the face of intellectually respectable Net stock bullishness--the belief that some of those companies will eventually make so much money that their now wacky-seeming market caps will look puny (not to be confused with the Ponziesque day trader creed of buying Net stocks because you'll be able to sell them to some sucker for even more). So when there are whispers that Meeker might be tiring of the sell-side grind, people listen. In December the rumor was that she was leaving for a job at dot-com incubator idealab. Meeker's response to an e-mail query from FORTUNE's Andrew Serwer was, in full, "no plans to leave mo' stan'...!!!" In an earlier interview with FORTUNE, though, Meeker expressed worries that her business was becoming "dysfunctional." So expect a lot more rumors--and maybe even some action--in 2000. After all, the Net stock boom over which Meeker has been presiding can't go on forever. Can it?

CHRIS GENT

A little over a year ago, Vodafone was an upstart British wireless operation with a weird name. But that has changed as the charming CEO, Gent, has quickly established himself as a telecom dealmaking force in the tradition of MCI WorldCom's Bernie Ebbers. Early last year, after hearing that Bell Atlantic had made a bid for wireless provider AirTouch, Gent swooped in with a bigger offer and nailed the San Francisco gem for $55 billion. Gent then smoothed the feathers of a cranky Bell Atlantic and got the two to merge their wireless assets--creating an alliance that will be rolled out as a new nationwide brand in the coming year. Closer to home, when Gent heard that Germany's largest wireless operator, Mannesmann, was eyeing a merger with Britain's Orange, he made a $107 billion bid for Mannesmann. A stock surge has since raised the offer to almost $140 billion. Mannesmann is still holding out, but Gent has shown he usually gets what he wants.

NOBUYUKI IDEI

Consumer electronics giant Sony Corp. is understandably giddy after a near-tripling of its share price in the past 12 months and double-digit sales growth in all of its major markets. But if you ask Nobuyuki Idei (left), Sony's dapper trilingual president and CEO, 1999 was just a warm-up. Idei will be satisfied only if the company can play a central role in the grand convergence of consumer electronics, computers, telecommunications, and digital entertainment. Indeed, Idei's most impressive accomplishment since becoming Sony's president in 1995 has been to morph the company's historically standoffish culture into one that embraces the cooperative attitude required to make it in the networked world. Now all the top management at Sony seems to buy in to Idei's vision of Sony as a "network company." As a result, Sony is being mentioned in the same breath as the Microsofts and Sun Microsystems of the world, as an arbiter of the future of digital technology.

LINUS TORVALDS

With the spectacular IPOs of Red Hat and VA Linux in 1999, the Linux operating system cobbled together by Finnish programmer Linus Torvalds (right) and countless hackers went from a vaguely anticapitalist crusade to big business (as of mid-December, Red Hat, which sells Linux software and consulting services, had a market cap of $17 billion; hardware maker VA Linux was at $7 billion). In the next 12 months we should begin seeing hard evidence of whether Linux really is the threat to Microsoft's Windows that those valuations portend. Meanwhile, Torvalds himself has been sitting out the Linux IPO frenzy. He does own some stock--gifts from grateful CEOs--but he's on to other things, see. He works free for a Silicon Valley chip-design startup called Transmeta. So far his project is very, very secret--but that too is going to change in 2000.

CONTRIBUTORS: Katrina Brooker, Geoffrey Colvin, Julie Creswell, Justin Fox, Henry Goldblatt, John Huey, Dimitry Elias Leger, Carol J. Loomis, Brent Schlender, Patricia Sellers, Andrew Serwer, Alex Taylor III