I'm about to begin building an iPhone game that will make use of Game Center Achievements and high scores, but I'd also like to have a version that works on iPhones that don't have Game Center (i.e. iOS version < 4.1). Can I have two versions of the same app in the app store, one for game center, one for without? Or should I design the app such that if the iPhone doesn't have Game Center, it won't make use of it, and if it does, it will make use of it?
I'm going to continue researching this, just thought I'd post this question and get some feedback in the meantime. Thanks so much!