Welcome to the site. No there aren't any special discounts or anything. Just cool new phone. I am also making the switch from Verizon. If your contract isn't up you will have to pay the ETF (early termination fee).
Make sure you get good coverage in your area first. AT&A is notorious for dropping calls so if that matters to you a lot you should reconsider getting an iPhone. I've been blessed with a 3G goddess so I get full 3G coverage wherever I go.
Good advice check your network first. Cool phones that don't make phone calls pretty much lose the cool factor quickly. I too switched from verizon to att and there are no incentives or deals. If your going to do it you will have to bite the bullet on ETF and other fees.