Google TV is Android 3+ with some UI changes to make it better suited for TVs. Eventually, I think they will merge Chrome OS's great looks into the Chrome app for all platforms (especially Android), or at least do some kind of merge with Android and Chrome.
I don't like the idea of having "one UI" for all form factors, like Microsoft tries to do. I think that will only lead to being optimized for one form factor, and significantly underoptimized for others.
Personally, I'd like to see them use some kind of "UI modes", so you have a phone mode, a tablet mode, a TV mode, and a desktop mode (which may or may not be the same as the tablet one, but would probably be better if they are kept separate).
Of course, they should still make them resemble each other as much as possible, but you can't use a tablet UI for a TV, and you can't use a phone UI for a desktop monitor. So when I dock the phone into a PC monitor, I want to see the desktop mode, and when I dock it into the TV, I want to see the TV mode, and so on. I don't think there is such thing as "one UI for everything". It may be good for one form factor, but for all the others it will be mediocre at best.
