Wii doesn't look that bad, depending on what your playing. Sitting and pointing the wiimote for some things isn't that bad.
Natal however...only if they had some decent action/fighting/DQ-swords-esque type of game....
Also - People can look fairly good while playing games. Decent headphones, decent set up. PC/online stuff. If it's not cool, then there could be something impressive such as the person's level of focus. Look at Touhou Project. And then look at Rhythm games. (DDR/ETC, For some of those, move your fingers fast, blah blah blah).
This however...watching others would probably make me want to run into a wall. Any bets on reports of broken objects with Natal?