During its fourth-quarter earnings call today, Research In Motion revealed that its upcoming BlackBerry Playbook tablet would be compatible with applications developed for Google's Android operating system.

Android app compatibility will come via a pair of app players, which RIM says will be available via the RIM App World. Using a special API, developers would easily be able to port existing Android apps to the Playbook tablet, RIM said.

The announcement comes with a catch, however. RIM says that the Android compatibility won't be available at the Playbook's April 19th launch. Instead, RIM plans to show off the features at its May BlackBerry World event taking place in Orlando, Fla.

Adding Android apps is essentially an admission that the App World app store hasn't been as successful as the company would like. About 20,000 apps are available on the App World market, but that is dwarfed by the 170,000 on the Android Marketplace. Adding the ability run Android apps on the Blackberry tablet OS will expand the universe of apps considerably, as the attention of app developers is focused there and on Apple's iOS.

The news comes after RIM posted a 32 percent jump in profits for the quarter. The company also reported record Blackberry shipments of 52.3 million, a 43 percent increase over the last fiscal year. RIM says that made the Blackberry the number one selling smartphone in  several markets. RIM's fiscal year ends Feb. 26.

RIM also reported that revenue for the year was $19.9 billion, up 33 percent from $15 billion the previous year. For the fourth quarter it was $5.6 billion, up 1 percent from $5.5 billion in the previous quarter and up 36 percent from $4.1 billion in the same quarter of last year.

Most of that -- 81 percent -- came from devices. Services accounted for 16 percent, and 3 percent was from software and other revenue.

Despite the relatively rosy picture, the company said during its earnings call that it was in a transitional period as it moved to a more tablet-centered product line.RIM will also face supply pressure as many of the components that go into Blackberry devices are made in Japan.