Apple showcased their upcoming iPhone OS 4 yesterday (and Twitter didn't crash!), which will include a games platform called Game Center. Game Center will add a backend to gaming on the iPhone/iPod/iPad, and will include such popular features as achievements and leaderboards. It will also act as a social games platform, where you can check out whatever games your friends are playing, which will help to spread games virally; after all, there are thousands of games available on the App Store and finding the good ones can be pretty hard.
There are already social game networks available on the iPhone, but they come from third-party developers such as Ngmoco, Scoreloop, and Aurora Feint. According to VentureBeat, it seems like these companies are actually looking forward to the release of OS 4 and Game Center, and plan to build upon the service using their already available tools.
iPhone OS 4 will be available for iPhone and iPod Touch this summer, while iPad have to wait until the fall (cynics would say that it will probably be released at the same time as the second generation iPad, but only the cynics...).