Japanese newspaper Asahi Shimbun recently carried an interview with Nintendo president Satoru Iwata, discussing the company's hopes for the year ahead, and he discussed a few very brief titbits about the possible DS successor and its features.
It will have highly detailed graphics, and it will be necessary to have a sensor with the ability to read the movements of people playing.
You may remember the DS receiving a motion sensor plug-in to play Tony Hawk's Motion, so this is hardly uncharted territory for Nintendo, but Mr Iwata reveals little of the possible motions that could be detected, though presumably it would involve iPhone-style accelerometers. The use of the phrase "it will be necessary" is certainly interesting, perhaps indicating titles are already in development for the console, though this could be the accuracy of the translation.
Further interesting soundbites came out of the interview, with Mr Iwata revealing the latest Legend of Zelda game for Wii is due to release this year, a rather exciting prospect considering nobody's actually seen the darn thing yet.