Angry Birds developer Rovio announced on its Facebook account a few hours ago that "AT&T is also working on enabling purchases from the Amazon Appstore soon," which would mark a pretty big move on AT&T's part since they've been firm in their resolve to keep apps from outside the Android Market ecosystem off their branded Android devices -- a frustrating (and arguably illogical) stance, to say the least. Well, first the good news -- AT&T has confirmed to us that they are, in fact, setting up access to Amazon's store:
"We're working to give our Android customers access to third party application stores. This requires updates to our systems and finalizing arrangements with Amazon. We will share more info with our customers in the near future."
The bad news is that AT&T's having any discussions with Amazon about this at all, which would seem to indicate that they're planning on making an exception to their Android Market policy for the Amazon Appstore rather than simply enabling sideloading on devices altogether and calling it a day. We suppose this could involve a round of firmware updates that drops the Appstore in ROM, but that seems like an awful lot of work considering how much red tape is involved in pushing even a single update for one handset on a major carrier. More on this as we get it; hopefully, AT&T subscribers will have their Angry Birds Rio fix soon enough.

[Thanks, Thomas]