Well, that's a nice discount on a non-contract phone. Is the additional discount due to a $100 rebate for qualifying data/voice plans?
As to which you should get: 1) which phone do you really want? 2) how do you feel about a contract extension?
I know you've been interested in Android phones in the past, and it looks like the Samsung Capivate will be coming to AT&T in a few months (their version of the Galaxy S high end Android phone with a 4" super AMOLED display and a 1GHz Hummingbird processsor). Otherwise, the iPhone 4 is certainly one of the nicest phones likely coming to AT&T this quarter.
-------------------- Lisa Gade Editor in Chief, MobileTechReview