According to a Bay area (San Francisco) user on Howardforums, T-Mobile is offering Nationwide Unlimited Voice plan for some of it's customers. Noted in the fine print, was that this offer is limited to loyal customers, who have been post-paid customers for at least 22 months. Perhaps a some kind of retention scheme for customers who are nearing the 2 year contract.
So according the same forum, Unlimited National Minutes for $49.99, Unlimited Messaging (any-type) $9.99, Unlimited Data $24.99 bringing everything unlimited to $85, beating Sprint's $99.
None of these figures has been officially confirmed.
HowardForum Discussion Thread
Monday, February 23, 2009