Recently bumped into an open source game intentionally developed for Android platform, which was started way back August 2009.
Replica Island is developed by an Android evangelist and Google employee, Chris Pruett. His blog discusses every little detail of the approach he did for this game. It would really be a good source of information about Android Game Development.
Get the source code at Google Code.
The game is already out in the Android Market so if you have your Android phone with you right now, I recommend that you try the game and see for yourself.