There's something about red that just seems ... different. After years of grey and black and white systems, something bright and pretty like this just blows my mind. The red is eye-catching and is perfect for Nintendo (home of Mario and a traditionally red logo).
Admittedly, though, this is a rare one. I went into my local Gamestop, and there were only two left and they just released. The guy at the counter said they wouldn't get any more, either. He had one, and I saw it, and it just made me want it more.
I already had a DS, but it sadly went dead (due mainly to spilling coke all over it, and even then it lasted a month or two more) and this is a wonderful replacement. The red is wonderful, and the backing is silver (where normal DSs are black). It also comes with racing decals (gimmicky, but kind of fun) and a special strap with a checkered flag pattern. I don't know how many people use those straps, but it'd look nice if you did ...
It also comes with Mario Kart, of course, one of the greatest games on DS yet. You can't go wrong with this. You have 15 bucks, get a wonderful system and an awesome game, and you look snazzy while doing so. Get em while they're still available!
(also, as an aside, original pictures of the revolution hint that red will be an available color. I hope so, because then everything will look awesome. remember, your DS will be able to connect to revolution, according to nintendo, as of this review. next year should rock!)