Existing users can keep the unlimited plan unless they want to add tethering. I think the real reason for the shift in plans is to reduce the impact of iPhone tethering, which will be rolling out this summer. The existing base of iPhones is already a giant bandwidth leech, and if you gave people a cheap unlimited tethering option it would probably sink the network.
I use less than 2GB/month myself, so stepping down to the tiered plan would probably save me money.
I use less than 2GB/month myself, so stepping down to the tiered plan would probably save me money.









