Apparently T-Mobile could be releasing the so called Android Cupcake version in May:
According to T-Mobile Germany, the software update is headed to G1 owners next month. As of right now, it’s only for the German folks. The US is still playing the waiting game.
I’m very excited with this news because the Cupcake puts Android definitely on top of the iPhone in features (it includes video recording something that the iPhone does not do unless you install 3rd party programs).