Seems the 32 GB iPhone is accidentally appearing on a lot of carrier websites this week. First T-Mobile Austria and now on AT&T.
On the site for AT&T's Blackberry Bold upgrade program (exchange current cell phone for credit towards a new blackberry) a 32 GB iPhone was listed as an option. Just more reinforcement that a 32 GB iPhone is on its way for the summer.
Interestingly the site listed upgrade values for iPhones. The 32 GB iPhone is listed as $335 in value and the 16 GB is listed as $205 in value. While trade-in value doesn't directly tell us how much new iPhone models will be selling for we might infer that the 32 GB will be $400 and the 16 GB will be $300.