RIM announced availability of its BlackBerry PlayBook OS 2.0, which adds some long anticipated features to the company’s tablet device.

The most obvious feature of PlayBook OS 2.0 is the addition of a native email app, which also offers a unified inbox consolidating messages from Facebook, LinkedIn and Twitter alongside mails. The lack of such an app was one of the most highlighted issues when the PlayBook was first launched,  being especially notable due to RIM’s established strength in messaging.

The update also adds a built-in calendar app which collects information from social networks, and a contact app which similarly is able to pull information from Facebook, LinkedIn and Twitter.

PlayBook OS 2.0 also sees the BlackBerry Bridge app updated, providing enhanced connectivity between a BlackBerry smartphone and the tablet. This includes a “remote control” feature, which allows a handset to be used as a wireless keyboard and mouse for a PlayBook.

The other headline feature is the addition of support for Android apps tailored to the PlayBook, which are available through the vendor’s BlackBerry App World store. While it has not stated how many apps are already available through this initiative, it has previously indicated that interest has been strong.

RIM has previously seen disappointing sales of the PlayBook, shipping just 150,000 units in the quarter to the end of November 2011.  The company has cut the price of the device drastically, in order to drive sales of its inventory.

While PlayBook 2.0 addresses many of the shortcomings in the device, it is late in itself – it had been anticipated for availability last year.