I think this is really interesting. Now that we're going to be getting LTE, there really is no advantage to staying with AT&T. I chose to stay with AT&T last year because of talk + web at the same time and the slightly faster speeds. This year, I have zero incentive to stay with them.
I bought my iPhone 4S the day it came out last year.
If they give me the full upgrade pricing, I'll stick it out with AT&T. They'll have made it worth my while.
Otherwise I'll either switch to Verizon (pro-rated ETF is pretty much the same as the AT&T upgrade fee), Sprint, or get myself an unlocked iPhone... hmmmmm
No advantage with AT&T? How about those with unlimited data?