My cable company now has an app for i-Pads where you can watch TV on an i-Pad.
Uverse from AT&T has something like that but only for certain networks. Most of those are owned by the mouse. Disney, ABC, ESPN and a bunch of others and not all of the shows are available.
It is an okay service but it would be great if you could watch the shows one saved with a DVR on a iphone or ipad. According to AT&T because of licensing issues that is hard for them to do.