I was thinking about this, I mean, when the GBA started to slow down in momentum, Nintendo released the SP version which pushed sales one hell of a lot for Ninty. I can't help but think that it was more reinstating style rather than the original advance's problems. The backlight was just a very big bonus.
I'm kind of a little worried Nintendo might one day re-release the DS as another special project. I just know I'd end up getting one, even though I'd be wasting money.