It looks like Google is working on it's own version of GameCenter for Android
I just found this and thought it was worth sharing - if Android games are getting their own version of Game Center soon it could likely be a feature that Gamesalad implements in the future 
http://venturebeat.com/2013/05/11/google-to-launch-google-play-games-platform-services-for-game-developers/

http://venturebeat.com/2013/05/11/google-to-launch-google-play-games-platform-services-for-game-developers/