I've upgraded my 2G iPhone to 3.0 and jailbroke and unlocked them. 3.0 runs very slowly, even without any Cydia apps installed. Push notifications aren't working, and P2P games aren't even supported! It's blindingly obvious that Apple is just very slowly phasing out the old phones, though they are still perfectly usable ones! Perhaps Apple should just release a new "iPhone S"! 😀