Though a couple of quarters later than planned, AT&T today said it would launch broadcast mobile TV services in May over Qualcomm’s MediaFLO network. Its initial line-up includes the same package of channels that Verizon Wireless features on its V Cast Mobile TV service, but AT&T promised today to unveil two exclusive channels, though it did not reveal what those channels would be.

The announcement comes right before CTIA Wireless kicks off next week giving AT&T a platform to show off its new service. The service is debuting with two handsets, the LG Vu and the Samsung Access, but otherwise AT&T revealed few details of the service and nothing about the two mystery channels it will broadcast.

MediaFLO uses 700 MHz spectrum to multicast high-power digital TV signals to handheld devices. While MediaFLO has a regular line-up of channels, which all of its customers will receive, Qualcomm owns enough spectrum to allow operators to strike their own deals with content providers and reserve specific channels on the network.

AT&T will be 16 months behind Verizon Wireless in bringing its mobile TV service to market. The company originally planned to launch before the end of 2007, but pushed its plans back. The delay probably had little effect, though. Mobile TV’s take-up in the U.S. has been slow, and Qualcomm hasn’t been able to launch service in all of its markets due broadcasters still occupying the spectrum.