3D inspired gameplay

Up until now, i figured that adding 3d to a game wouldn't really add much (though I haven't see any 3D games).  But I just thought of one game type/genre that could really use 3D. That would be the old NES/PC style top down games ( Top-Down Perspective), not the LTTP top down, but like those particular contra levels or I'm sure many other games where you see only head and shoulders. With 3D you could add a depth where jumping and platforming made sense, plus you'd get all the coverage of the top-down perspective. you'd be able to have flying enemies and traverse mountain cliffs without it looking really weird because of the perspective. I'm actually pretty excited to see this kind of game come out.
 
Can anybody else think of other areas of gameplay which will benefit from 3D other than it just looking more 3D?

You ask the question everyone in the industry is also asking. No one has been able to figure out a reason for 3D gaming to exist other than adding to the level of immersion. If done right that's enough of a reason, but currently the amount of technology required to achieve a believable level of 3D immersion (glasses, three monitors) is too high for the average consumer.

3 monitors? WOW

I have another example that I remember hearing over the past week. Sorry I can't remember who brought it up.  But, you know in Mario when there's a star high in the sky and you can't quite figure out where it is. Then you look at the shadow and you can figure it out. I hope with 3D I can grab that star without looking at the shadow.