We kind of knew that the Amazon Appstore was coming, although until Rovio announced that it would be the place to grab Angry Birds Rio first, we didn't have anything official.

But now we do, and not only that, but a brand spanking new Angry Birds adventure to look forward to as well. Bi-winning.

The Amazon Appstore (all lower case letters and one word on Amazon's landing page - what will Apple say about that we wonder?) will be offering the Android version (paid, ad-free) of the game before the Android Market gets it - although Rovio has since confirmed via Twitter that iPhone and iPad users will get the film-franchise based game on the same day (22 March).

The Amazon platform will also host ad-free Android versions of the two existing Angry Birds titles (the original and Seasons) as well.

“The Android platform has seen phenomenal growth, and it’s great that new avenues for app distribution are opening up,” said Mikael Hed, CEO of Rovio. “The openness of the Android platform works for the benefit of consumers and developers alike. It has been delightful to team up with Amazon to bring the Angry Birds franchise to this great new application marketplace.”

“Amazon is thrilled to work with a leading developer like Rovio in offering our customers Angry Birds Rio for Android exclusively in the Amazon Appstore,” said Aaron Rubenson, category leader for Amazon Appstore. “We think Angry Birds Rio is sure to be an instant customer favourite.”

Angry Birds Rio will have 60 new levels to begin with and will feature birds from the Fox blockbuster animated movie.

The exclusive deal with Amazon throws open some interesting questions and also adds further fuel to the argument that the Android ecosystem is becoming more and more fragmented.

Rovio also confirmed a webOS version for Rio is incoming.