Simply because of their new controller, it will open up a whole new doorway to interresting game play and concepts. I hope it works.
But as mentioned, I want one, sadly, for its backwards compatability with NES and SNES
There are just so many cool games I want to play again. And if Nintendo adds a "save" feature, so you can "pause" your game, for all those games that didn't let you save, they will be the BOMB! Imagine, now you won't have to spend an all-nighter beating a NES game because you can't save, or leaving the NES console on all night and day so you don't loose your game!
I surely hope you can save, lol.
As far as graphics goes, and this is probably totally subjective, but I've always prefered Nintendo's style. To me, other consoles were very blocky and triangular and had a weird refresh flicker, such as the PS2. But Nintendo also seems more fluid and more round then triangular. Almost cartoony. And I like those kinds of pretty, colorful, fluid graphics. Over the more rigid and blocky of other systems.
My thinking may be totally wrong, but that is simply how I perceive it.
Not bashing other consoles, just saying that I choose Nintendo, they always have something new to offer, even when the same names are attached to the game titles. Just look how Metroid evolved, and yet it's still popular. And look at all the funky ways they changed Zelda, different controls, styles, looks. And mario, with its side-scrolling to RPG to Paper Mario and so forth. They keeps things exciting. And they make the most radical changes. Risky, but most of the time successfull.