The terrestrial mobile Tv services have always had a serious handicap- that of requiring a tuner in the phone. Unfortunately, vendors did not see reason enough to include these in their new releases such as the IPhone4. This means that millions of devices continue to be sold which have no capability for terrestrial reception. One reason has been the patronage of new devices by Telecom carriers which have interest in the usage of their networks rather than off the network usage.
It is not only the US which has been struggling with terrestrial Mobile TV. In Europe the story is similar, with DVB-H failing in country after country and Spain having said "No" to mobile TV so far as terrestrial allocations are concerned.
In any event, time is now running out on terrestrial mobile TV. When LTE comes in, the capacity on networks will be enough for all. And it will not require special phones But mobile TV, on the 3G and LTE networks is set to grow exponentially.
http://mobiletvhome.com
Could be a nice little earner for them if they can sell off the spectrum too.