AT&T and Apple haven't released the terms of their exclusivity agreement. I guess the point I was trying to make is that Apple won't waste R&D dollars to develop an iPhone that would run on a technology that will be replaced in a couple years (CDMA). Apple's more about new, groundbreaking and innovative. Thus, when we see a Verizon iPhone, it will be new, groundbreaking and innovative. What better way to make it so than introducing a 4G phone before the competition?
The only problem is that Verizon's 4G/LTE network won't be operational until the second half of 2010. And even then it will only be available in 20-30 markets. AT&T's won't be operational until 2011. So while theoretically we could see an iPhone on Verizon in 2010, I think it's much more likely that Apple waits for AT&T to catch up to Verizon, in order to simplify production. That's why I said 2011 at the earliest.