T-Mobile Flexpay Eliminated (Phone Calls from Customer Service)

Just got a call from T-Mobile claiming they're getting rid of the flex plans - the plans that resemble a pre-paid plan but have text and data included (mine is like $65 a month for 500 minutes, unlimited text, I believe unlimited data). They're saying my two options are to go fully prepaid (which I think doesn't include data) or to go on a normal plan which requires me to sign up for a contract.
They said they couldn't provide any comparison in writing, and that the website hadn't been updated to reflect this (since it looks like you can still sign up on the Monthly4G plans).

At the time of the call, I assumed I'd have to sign up for a post-pay contract and that I'd rather get a free phone that I want (like a top of the line Android) than stick with my current phone.
I'm currently on a Nexus One with the same plan as you (500 minutes, unlimited text and data). I think this plan is awesome since I got my Nexus as a gift and there was no need to pay for a contract rate when I wouldn't need to use the plan to subsidize a nice phone.
I think we can sit tight for now as according to this site are plans are grandfathered in as of July 24th. I'm not sure how accurate these are, but it seems if we don't do anything we'll just be paying the same amount albeit for past usage and not future usage.
The calls make it seem as though we HAVE to pick a new plan right now, but I think it's a guise. The current management probably are trying to switch as many as possible off of the grandfathered plans and onto solid post-pay plans to prevent subscriber leakage to other providers. They've already been hemmoraghing tens of thousands of subscribers already to the big two: Verizon and AT&T.