I posted a few key differences between the iPhone and the G1 over at Onxo .
I found some explanations explaining the difference at Network World that warrants reading and I highlighted some important ones.
At the same time, it's only been a day or so since the unveiling of the G1. It's worth noting that things can change between now and October 22nd.
Particularly, I'm hoping T-Mobile will realize the 1GB cap on 3G access is pretty stupid.