Didn't Sony call the DS a gimmick?, I bet Nintendo hopes this ones turns out just the same!
Talking of demographics, designing a handeld for 8-9 year olds with dual screen and stylus control makes even less sense than 3D.
They never called the DS a gimmick..also, it wont since SONY has announced long ago that the Playstation 3 will offer 3d gaming/movies this year..
although the need for glasses is there. If a 3d tv costs that much, I can only imagine how much a 3DS will cost with a screen that can do 3D without glasses, if tv's with glasses cost well over 2k.