It looks like T-Mobile is doing a "spring refresh" of their rate plans on May 22nd. They will be getting new Family plans and Individual plans and data plans as well. For some of the details, here's a quote from the TmoNews article, or you can check out the pics:
We’ve since learned that T-Mobile will in fact being doing a revamp of their entire rate plan lineup including both new Individual and Family Plan rates. The new Individual plans will mirror the new family plans with three options: 500 minutes, 1000 minutes and unlimited.

500 minutes will go for $39.99 for just talk, $49.99 for Talk + Text all the way up to $109.99 depending on what kind of a data package a customer chooses.
For 1000 minutes the price goes up to $49.99 for voice minutes but no texting or data plans can be offered at this price point. Customers are bumped up to the Unlimited plan.
The Unlimited plan starts off at $59.99 for Talk + Text with no voice only plan. The current $79.99 promotional plan for unlimited talk + text and 2GB of data remains an option. A customer can choose 200MB of data, 5GB of data or 10GB of data for $69.99, $89.99 and $119.99 respectively.

Source: TmoNews.com