So will the Nexus One work on AT&T?

The phone will work with any GSM carrier if unlocked but 3G will only work with Tmobile or other carriers that share the same 3G bands. If you're on AT&T you'll still get EDGE but no 3G. Rumor is that a phone with Moto Blur will be the debut android phone on AT&T but until that comes out, no 3G android for AT&T customers, unlocked or not.
 
The phone will work with any GSM carrier if unlocked but 3G will only work with Tmobile or other carriers that share the same 3G bands. If you're on AT&T you'll still get EDGE but no 3G. Rumor is that a phone with Moto Blur will be the debut android phone on AT&T but until that comes out, no 3G android for AT&T customers, unlocked or not.

You don't know this for sure. The rumor floating around from a reliable sourse says the unlocked version will be at&t 3g bands 850/1900. Would be kinda stupid to have an unlocked t-mobile band version AND a locked t-mobile version. Itw ould be the same phone... duhh
 
You don't know this for sure. The rumor floating around from a reliable sourse says the unlocked version will be at&t 3g bands 850/1900. Would be kinda stupid to have an unlocked t-mobile band version AND a locked t-mobile version. Itw ould be the same phone... duhh

Unlocked or locked, the phone uses Tmobile's 3G bands. Read the terms of sale and the only carrier listed is Tmobile. The unlocked version is for users who do not wish to get a new contract whether they're on Tmobile or AT&T.