Sprint's riffed about the possibility of migrating to LTE in the past -- as has its 4G partner, Clearwire -- so it's no big surprise to hear CEO Dan Hesse tell the Financial Times today that he's still open to the idea down the road, possibly side-by-side with the company's existing WiMAX deployment thanks to its deep spectrum holdings. What's far more interesting, though, is his concession that there's "logic" to exploring a merger with T-Mobile USA in the event that they both move to LTE for their next-gen networks. For its part, T-Mobile hasn't announced its 4G plans yet, but it's an open secret than Deutsche Telekom has explored the idea of selling off its US outpost in the past. Combined, it seems that Sprint and T-Mobile -- neither of whom have the firepower to compete with giants AT&T or Verizon on every level -- would create a strong third-place carrier capable of nipping at their heels. FT says that the idea of a Sprint deal was rejected back in 2008 on grounds that the two have incompatible networks, so who knows... if that restriction were removed, there might yet be love in the air.