Evidently, if you choose a BB Minutes and Mail plan you may have to extend your contract with T-Mobile. Here's the "fine print" from their site:
*Promotional plan will require a contract extension.
If you select a promotional plan you will not be able to make further changes to your plan online until after it has taken effect at the start of your next billing cycle. If you require further assistance, please call Customer Care at 1-800-937-8997 or 611 from your mobile phone.
Still seems like a pretty good deal, since I just signed up for a 2-year contract about a month ago. I'm currently on the $39.99 "Get more 1000" plan with unlimited BB for $19.99. If I choose the $59.99 "BB Minutes & Mail" plan I receive unlimited text messaging for basically the same price as my current package. Am I reading that correctly? Plus, it looks like TMo has recently increased the fee for the BB unlimited to $29.99.