Best hire or promotion of 2012: Marissa Mayer. Take a struggling, demoralized tech giant with a faded Web brand and dimming prospects. Add a strong dose of glamour, smarts, tech cred and product vision, and bingo, you have a company that's exciting again. Of course, Mayer's challenges at Yahoo are enormous. The odds of pulling off a turnaround are arguably slim. But there's no question that it will be fun to watch.
The company just introduced three gorgeous new devices. Here's proof it wasn't always so adept.