This is starting to look less attractive for me. Because I am not in my upgrade window, it looks like there will be at least a $200 premium added for me. Additionally, it appears that they are indeed limiting the $30/6GB plan to voice plans of a minimum rate of $35/month, so mine would not be included. To switch to a more expensive plan would actually get me less because mine is an old plan and has some retention modifications to it. So, if I switch to a $35 plan, I lose features. This is the same problem I had with the original iPhone plans, that is to get one of their iPhone plans would claw back existing features or triple my bill.
I still think this is a good deal for new customers and existing customers who are in their upgrade window and have a $35 or higher plan already.
Where does it say that you need a >35 for the 6gb plan? I see nowhere that it says that other than people speculating.