I was reading ZDNet when I came across this interesting comment.
If this is true, those of you who can wait for a few months after the June 29 launch of the iPhone, stand to be rewarded for your patience.

As Wes Leopold commented,

I just got off the phone with an ATT Rep who said that there are no rebates for the 2 year agreement towards the phone. He said that Apple has released information on a NEW IPhone that will be 3G and 12gig with new features that will launch in 6 Months. So for those of you who can wait, in 6 months you can get a killer IPhone or get a used 8gig/4gig from someone selling there old one to get the new one,