I have been playing with PlayOn on my PS3, but I'm pretty sure it works with the Xbox as well.

PlayOn gives you access to Hulu, Netflix, CBS and maybe something else I can't recall. I've only checked out the CBS and Hulu feeds, but the results are quite good. 16:9 content fills the screen and generally looks higher-res than SD DirecTV. The video seems to be less than 30FPS, but it's certainly usable if I happened to miss a show.

Actually, I have been using the PS3 a whole lot lately to watch television I've downloaded. It actually makes me question the $100+ I pay DirecTV every month. If the PS3 had a DVR function for OTA, I could consider pulling the plug on DirecTV at this point. At the very least, I'm considering scaling-back my programming tier quite a bit.

The PS3 has been one of the best entertainment purchases I've ever made, and I don't play games.