roku (Score 1)

Roku (http://www.roku.com/) + http://github.com/netguy204/roku_media_server

and more Roku based solutions to be arriving soon, now that Roku has opened up the API. It's not exactly what you're asking for, for now you need actual downloaded files encoded in one of the several formats that Roku supports, but beyond that tiny hurdle, works like a champ!