Since its release back in December, Angry Birds has become nothing short of a phenomenon. The popular iPhone game has just passed the 6.5 million download mark, with the free Lite version exceeding 11 million downloads. These numbers are still miles away from developer Rovio’s target, however, as their head of North American operations Peter Vesterbacka recently told VentureBeat “our goal is to get to 100 million paid downloads.”

It’s a lofty target, but it’s not one that may be entirely out of reach. In addition to the iPhone version, Angry Birds has already spread its wings on both the iPad and Nokia N900. More devices are on the way including Android phones, more Nokia phones, and Palm devices. There are also rumblings of a possible PC version, and while no one has said it out loud yet, it seems safe to assume that Windows Phone 7 is likely on the table. Rovio calls it the Tetris strategy – put the same addictive experience on as many platforms as possible to reach the maximum potential user base.

It’s a strategy that’s been proven to work, and not just with Tetris. PopCap Games has embraced this business strategy for years now and it’s built them into one of the leading voices in casual gaming. Could Rovio be the next big name in the business?

Until they follow Angry Birds up with another release, it’ll be hard to say. Their previous efforts have hardly been runaway successes, but then again, their past catalogue is largely comprised of games created under a “work-for-hire” arrangement. Angry Birds is really the first notable game from Rovio where they’ve been able to put themselves in the spotlight.

If Rovio can manage to keep caging those birds in new locales (note to Rovio: Angry Birds would excel as a download for console gamers), and if they manage to pull off another game of this calibre, the title of “top notch casual games developer” shouldn’t be a hard one for this fine-feathered developer to capture.