We've been planning for some time now to leave Verizon as soon as our contract expires. While the network is very solid, and the customer service has been decent on the rare occasions we've needed it, I've long felt like we were paying too much for hubby's data plan. I have been terribly dissatisfied with sluggish MobileWeb, and became even more so after they added advertising to it with no improvement whatsoever to the speed or functionality, and without so much as an opt-out option (I pay for the lousy service -- why do I have ads on it?). We've also found their phone selection lacking. Even if the Palm Pre hadn't wowed us (/covet), we would have migrated.
However, even if all those other negatives didn't exist, we'd still move because of this: