MacRumors.com

Engadget claims that AT&T is working on plans to offer IPTV (Internet Protocol TV) through the Apple TV:

A well-connected source tells us that AT&T and Apple are working on adding IPTV capabilities to the Apple TV beginning sometime next year. (A launch window hasn't yet been determined, our source says that plans are still being worked out.)

Few details are available, but AT&T does offer a form of IPTV with its limited U-Verse service now. Whether this represents full TV programming through the Apple TV, or simply on-demand programming, remains unclear.

Apple did recently announce added functionality to the Apple TV, in the form of YouTube video support to be launched in June.