First of all, unless Apple decides to sell unlocked phones (which I'm hearing is very possible), the new phone will have a new bootloader, which means back to the drawing boards for the hackers. When the 4.09 bootloader came out, if you recall, it took months to unlock the iPhone again.
Second of all, even if you get an unlocked phone you can forget about 3G for a long time:
- AT&T runs 3G at 850Mhz and 1900Mhz. T-Mobile USA runs 3G at 2100Mhz. Unless Apple supports 2100Mhz as well, 3G will never work on the iPhone under T-Mobile. However, Europe uses 2100Mhz, so you might be able to get a hold on a European iPhone and unlock it. Big hassle tho if you ask me.
- T-Mobile only offers 3G in New York currently. They have plans to release it nationwide, but it will literally take years. You'll have to check their release schedule for your specific state.
I'm on T-Mobile USA, and I'm thinking I'm gonna have to switch back to AT&T. Not too worried but it just means another break the contract $200 fee, which always sucks.
Correct me if I'm wrong on any of this...