Here's what you do-
1- Return it before it drives you nuts and you end up paying $350 to leave AT&T, yes that's the termination fee for AT&T now. Fortunately for me, I left before AT&T smarted up. When I got laid off, I quit AT&T because, quite frankly, I would have missed several calls from prospective employers had I stayed on AT&T. I am now with a Verizon Motorola Droid. It's a good phone, do I miss the iPhone? You bet- the apps, the games- it's slim pickings. But where I was once without service, I can now make calls, surf the web. I miss my NYT app, my redbox app- but then again, what good is making a rental reservation on an iPod touch without a connection?
2- Find out which carrier is the best in your area
3- Pick out a phone you like. If you want an iPhone-like experience, then go with Android. If you really, really want the iPhone and want to see if it's on Verizon come June, then use your old T-mo phone x 1 month and wait and see. Personally, if I were you, I'd wait to see if it ends up on Verizon next month (that is if Verizon is any good in your area).
In it's current state the iPhone is a fantastic device, but a lousy phone.(where I live) I don't care if it's AT&T's fault or Apple's fault. At least in my area, it is a joke of a phone. Where I live- NYC/NJ- it's basically a $70/mth iPod touch. And I doubt it's the phone because everybody complains about it. Which I think is ridiculous- all these people whine, and moan, and get angry about the iPhone and at the end of the month, they fork over $70+ to AT&T. Wake up, if the service sucks, switch.
I don't care if the next iPhone has a 3D hyper-OLED display with holographic display option, mind control, and a battery that lasts a week, and has a PS3 emulator on it that renders all the games in 3D. The only thing I want to know is- will it be on Verizon (best in my area)? In fact, I'd rather have the EXACT same 3GS running on Verizon than a hyped up iPhone on AT&T.