The nation’s number four carrier is once again pressing ahead with its big HSPA+ expansion, announcing today that speeds of up to 21Mbps (theoretically, of course) will be available in over 25 metropolitan areas covering more than 75 million folks by the end of the month. In conjunction with the expansion, that means that T-Mobile’s webConnect Rocket USB modem will be available in the newly-upgraded markets, which include LA, Dallas, Atlanta, Houston, Seattle, Tampa, Orlando, Pittsburgh, Charlotte, Oklahoma City, Tulsa, and New Orleans, among others. Interestingly, the carrier isn’t shying away at all on its questionably-truthful “4G speeds” talk despite some pooh-poohing from rivals, so we’ll have to see whether the claims hold up once the networks start to build up a little saturation. No KC 😦