That'd work for except for the fact I don 't like the idea of being tied to a specific TV. Samsung at the moment, sharp in another room, panasonic in another, LG elsewhere. I'd rather the black box.
Perfectly honest...a TV standard for slotting in adaptors like the old PCs...standard slot, slip in the ATV, whole new interface. Want googletv...slip it in, another interface. The TV supplies the network, power, etc, the slot allows you to choose who's style you go for.
Let the TV manufactures devise a universal standard slot, let the content distributors (Apple Google etc etc) build to it. And actually, this would fit right in with S.Jobs statement about having to take the TV back to basics to get it right this time. Fully flexible. Hell, even the memory needed could be built into the TV itself.