Unfortunately, Rovio reported that they had no intention of delivering Angry Birds for the new Microsoft OS. They said that their app writer had "NOT committed to a Windows Phone 7 version." Not only that, Rovio said that Microsoft didn't ask permission to use the Angry Birds image.
Might we have yet another lawsuit on our hands? Probably not. But it is interesting to think about the disconnect with their marketing department. Was it their intention to give the impression of a WP7-bound Angry Birds? Was it just wishful thinking that the game would eventually arrive for their OS?
Microsoft doesn't have to fret too much about removing the one app from their marketing material. Their game titles for Windows Phone 7 include games as Bejeweled LIVE, UNO, Rocket Riot, Assassins Creed, and Guitar Hero 5.
Despite this hiccup, Rovio still might offer an Angry Birds for Windows Phone 7 in the future. Should the OS gain a significant piece of the market, Rovio won't miss out on the opportunity to cash in.
source: Electronista, Microsoft