Research in Motion showed off its PlayBook overhaul in October, but PlayBook 2.0 wasn't released until Tuesday.
NEW YORK (CNNMoney) -- Research in Motion has finally launched a much-needed update to the PlayBook tablet, which now includes built-in features like email and calendar.
BlackBerry maker RIM (RIMM) began selling the PlayBook in April 2011. The tablet immediately drew criticism for its unfinished feel.
The major head-scratcher: The PlayBook lacked built-in, native apps for key functions including email, calendar, address book and BlackBerry Messenger. Tablet users had to connect to a BlackBerry smartphone for those functions.
Most of those problems were remedied on Tuesday, when RIM released the 2.0 version of the PlayBook's operating system -- an update that was originally slated for November.
PlayBook 2.0 includes native email, calendar and address book; integration of contacts with social networks like Facebook and Twitter; better Web browsing; an updated virtual keyboard; and other minor improvements.
The update does not include addition of the popular BlackBerry Messenger service. Back in October, when RIM announced via blog post that PlayBook 2.0 would be delayed, the company said of Messenger: "We're still working on it."
Beyond the Messenger void, PlayBook 2.0 finally gives the device features that are standard on other tablets. But it may be too little, too late.
PlayBook problems: In early December, RIM warned investors that sluggish PlayBook sales and a massive BlackBerry service outage would hurt its third-quarter results. When the company actually reported earnings later that month, it revealed that it shipped only 150,000 PlayBook tablets.
That was a drop from the already paltry 200,000 PlayBooks shipped in the second quarter, and the 500,000 shipped in the first quarter.
By comparison, Apple (AAPL, Fortune 500) sold a record 15.4 million iPads in its latest quarter.
But RIM's troubled tablet is just one of a number of problems plaguing the company. Late last year, RIM suffered what executives later called the largest-ever BlackBerry outage, which took down service for three days.
RIM shares fell severely over 2011, and some disgruntled investors began pushing to remove and replace RIM's board.
Last month, RIM named Thorsten Heins -- formerly the company's chief operating officer -- as its new chief executive officer, succeeding co-CEOs Mike Lazaridis and Jim Balsillie. Critics balked at the appointment of an insider, but RIM shares ended up gaining nearly 15% in January. 
