According to Phandroid, the option was removed from the website for a short while and then reappeared. AndroidandMe.com reports that Telus and Bell also work with this phone.
This new development is great for AT&T users who wanted an Android phone. The Motorola Backflip which was released not long ago was locked by AT&T in terms of where you could download apps from.
For those of you who saw these figures about the sales figures of the Nexus One, maybe this move will spur purchases.
Image from engadget.com