Following the release of iOS 4.1 for the iPhone and iPod touch earlier today, the first Game Center enabled games have begun to appear on the App Store. Pangea Software has released updates to Nanosaur 2, Cro-Mag Rally and Enigmo, enabling support for Game Center achievements and leaderboards for single-player games as well as multilayer Game Center support including Voice Chat and Auto-Match. FireMint has also updated its iPhone and iPod touch versions…