Nintendo's Reggie Fils-Aime dropped by Late Night with Jimmy Fallon last night (on his birthday!) to demonstrate a few of the 3DS's AR functions to Jimmy and his audience. You've never seen anyone have so much fun shooting tiny arrows at imaginary targets before. After that Reggie plays a game called Face Raiders, which sounds like an entirely different kind of action, but actually just has him shooting tennis balls at floating versions of Jimmy's face.
WIthout being able to show off the real 3D in commercials or on TV, I guess these AR demonstrations are the best Nintendo can do for now, even though they're not much of a stretch from what the DSi or most smartphones can already pull off. Hopefully hearing a talk show host call the 3D effect "nuts," "insane," and "mindblowingly awesome" is enough for any doubters to get out and take a look for themselves.