Reuters reports that AT&T is working on iPhone applications that will tie the handset to its U-verse TV/internet/phone service.
The iPhone applications under development would presumably interact with the U-verse subscriber's set-top box (required for u-Verse service). Reuters describes applications that could be used to listen to voicemails on the user's TV, act as a TV remote control, download shows from the DVR to the iPhone, or throw virtual tomatoes at the TV.
Pricing information and a projected release date is not available as of this writing.