An interesting Android pattern, along with the Kindle Fire; also see Facebook Not Building a Phone*
By customizing Android, the Facebook phone might not be able to include some Google-developed apps like Gmail, Maps, or possibly even the Android Market. Instead, it could replace the Android Market with its recently launched HTML5 platform, and provide single sign-on where users could instantly access any these Facebook apps without having to reenter their credentials. This could in-turn help it fight off the Apple App Store, turn Android against Google, and make more money through in-app payments powered by Facebook Credits. It could also tap Bing for maps and let a web browser snagged through its acquisition of Parakey provide access to other services.