What I would be interested in buying (when I'm making more money than I am now) is a 'Surface' that can tilt.
Option A - Desktop
Remember Star Trek the Next Generation, with their handy touch consoles? Remember how they weren't parallel to the ground? They were maybe 45 degrees tilted, so you could read them without having to crane your neck.
Have something that can tilt, less than a meter across, something that will fit on a typical desk at home, at a library, or at work.
You can either have it tilted for everyday use (typing documents, browsing the internet), put it flat down if you and your friend want to play air hockey or minesweeper or something, our tilt it vertical if you just want a screen to watch things on.
Option B - The Big One
A dining table-sized 'Surface,' which can tilt from dining table to white-board/television, and which you can control either by touch or by wireless keyboard/mouse.
Mount it on a sturdy axis so it can either sit flat or perpendicular to the ground. If the legs had lockable wheels so I could roll it against the wall or out into the center of a living space, that would be ideal.
I figure you'd put it in your living room or study/office. When you have a big group activity or just want a lot of space to work with, you have it in table mode, and you use it as a touch screen, probably relying on the on-screen keyboard if you need to type things.
Or you can put it in screen mode, for movies/TV/Modern Warfare 3, or for presentations like a whiteboard, or as just a computer screen if you want to sit on the other side of the room and control it with a wireless keyboard and mouse.
If you want perfect functionality, you model the wireless keyboard on one of those nifty laptops they have now where the screen can swivel and flip shut so the screen is facing out, only with this one you can also choose to have the keyboard side up. That way, it can work as a laptop on its own, or you can use it to control the Surface screen at home.
Basically, you try to get the perfect mix of TV, desktop computer, laptop, and remote control. And make sure it can tilt, because nobody wants to use the screen while standing all the time.