Correct me if I'm wrong, but if you have been grandfathered in with the unlimited data plan with Verizon- are they now requiring you to switch to the 2GB for $30/5GB for $50 deal when you re-up your contract?
Only if you want to renew the contract. But the only reason why you would ever renew a Verizon (or any carrier for that matter) contract is to get a discounted phone. If you're willing to pay full price for whatever phone you choose you continue on your existing contract with your new phone.
Because I steram Netflix and TuneIn Radio at work I will easily eclipse 10 gb a data a month - I'm closer to 16. Even if I were to cut back to 10 gb, that's something like $100 more a month than I'm paying right now. I would end up spending less by buying the phone outright than renewing the contract - and it wouldn't even take a year to start seeing the savings. Plus, since I'm not under contract, if Verizon decides to start screwing with me I can leave at any time because I'm not weighted under a 2-year contract.
The thing is, though, I like Verizon's network. It just works, and it works just about everywhere. My brother-in-law has Sprint and he doesn't even get 4G coverage in the Detroit Metro area when he comes to visit. I'd rather stay with Verizon as long as I can, at least, until customer service becomes so crappy that I'd be willing to switch to a lesser network for better service.