Unfortunately not. Verizon and T-Mobile use different network technologies (CDMA for Verizon and GSM for T-Mobile), and a phone that is compatible with one won't be compatible with the other. There are rare exceptions (when phones have both a CDMA and GSM antenna), but the iPhone isn't one of them.
The only way to get an iPhone on T-Mobile at the moment would to get an unlocked AT&T version or buy a factory-unlocked phone directly from Apple. Even then, iPhones aren't completely compatible with the T-Mobile network. At best, you'd be getting around 2.5g (EDGE) speeds.