Back in August, Verizon turned heads when it said it would begin to use "Network Optimization" for those few customers still on the old unlimited data plans. In layman's terms, it meant that Verizon intended to throttle the speed of the top 5% of unlimited data users on LTE networks, something that's already in place on the carrier's aging 3G system. But today, the very first day that the policy was set to go into practice, the company seems to have backed down.
Update: In response to the rather vocal outcries of many of its subscribers on the web, Verizon has clarified what will happen to 3G/4G data plans explicitly. The takeaway is this: anyone purchasing a smartphone from this summer forward on subsidy pricing will be pushed into tiered/shared data. If you choose not to buy a smartphone on subsidy, you can keep your unlimited plan if you choose to.
This means if you renew your 2-year agreement, from this summer forward, on any line by buying a "discounted" phone, you lose unlimited.