I think it's funny that everyone is upset at all these changes, even though it simply puts Sprint more on par with the other providers. Sprint is a company that is in 3rd place, and showing no signs of being able to compete with ATT and Verizon. Sprint has to find ways to be competitive. Landing the iPhone and possibly iPad will be good for Sprint. Combined with the unlimited data, that could potentially bring in new customers.
New customers means more money, which means more money to build out their network. In my opinion, Sprint needs to take this money, and add to their network structure. By keeping the unlimited data, they can draw new subscribers, but need to continue to work on providing the network capacity to support them. The worst thing they can do is repeat what happened to ATT and add tons of new customers, but provide them with questionable service.
Paying for this means that cuts have to be made somewhere else. I have been a Sprint customer for over 11 years, and I can honestly say that none of these changes will impact the service that I receive from Sprint. Yeah, getting an upgrade every 12 months is nice, but only if I want a new phone. The other "perks," in my opinion, were useless. I don't need someone to review my plan. I don't need a discount on accessories that I can buy hundreds of different places. I think the premier plan was overhyped from the beginning, and never really amounted to much of anything.
I would guess that there are a very, very small number of people who will say they switched to or stayed with Sprint because of this program.