Well... that didn't last long. After we reported just a couple weeks ago that Angry Birds Rio would be an Amazon Appstore exclusive, it lasted only a week there, and is now on the Android Market. Obviously, the exclusivity was a marketing deal between the Amazon Appstore and Rovio, but it is still surprising how little time it lasted. Regardless, you can head over to the Android Market or the Amazon Appstore and pick it up for free if you haven't already.
Source: Android.net via Phandroid