I'm not sure, I just saw an update for them yesterday through the app store, went and upgrade through that, in the comments it said game center. Then loaded it up, exited, went to game center and saw the achievements in there. Feel free to add me and see if mine show up on your end. Also, its World War Desert and iMobsters Don if that makes a difference, dunno if they still have the old ones lingering around.
That helped. Thanks. I downloaded World War Deser and iModsters Don and it still didnt work at first... but after doing 1 attack in each game the little "Welcome back petedodd" popped up and now gamecenter is turned on for both. Awesome.
Kubb multiplayer Kubb confirmed to be a gamecenter multiplayer app (by me). Plus it's free right now!
Gamecenter update for super mega worm is out now. Has leaderboards, achievements are coming in the next update
Haven't heard anything from Gameloft or EA or any other big publisher... but you have to assume it's coming. They would be insane not to support it. But maybe they hate money.
Stardunk is now live with GameCenter support. You can play basket in massive online contest with your gamecenter account and earn up to 19 achievements. http://itunes.apple.com/us/app/stardunk/id361152652?mt=8