The new revolution on mobile platforms is going to be the Android OS from Google. Since it is open source and adheres to the Open Handset Alliance.
The T-Mobile G2 (HTC Magic) is going to one heck of a phone. Google should have eliminated the glitches from the first gen G1. The degree of customization available on the Google phones are mind boggling. And if you have the inkling, you can develop applications for your own phone, since its open source.