So you you have to sign up for a two-year contract with them? If so it doesn't quite eliminate the two-year contract, but gets you out of your other contract and puts you on theirs.
My issue with T-mobile is they don't give a **** about their long-time costumers. My mother was with them for over 10 years(since almost the launch of their wireless services) and they didn't bat a god damn eye when she eventually left because of their shoddy services and customer support. It seemed like the longer you were with them, the worst their deals were for you.