Iwata said the DS2 (that's what we'll call it for now) will have motion-sensitive controls — think Wiimote, or at least iPhone accelerometer. He also promised it will have "highly detailed graphics," which haven't been a priority for Nintendo lately. Maybe he just means they'll be detailed compared to what we see on the DS right now, though.
He also said the DS' successor will definitely not have a 3G Internet connection or monthly fees to accompany it. The iPhone poses a significant challenge to the DS and the PSP in the mobile gaming marketplace, and it has done so with an available-anywhere App Store full of small affordable games, including social ones that take advantage of the 3G network.
A 3G connection on the DS2 would have been a step in a new direction for hand-held gaming consoles, but maybe people aren't ready to pay a monthly fee just for portable games. Are you open to buying a DS2 anyway or do you think cell phones will take over your mobile gaming habits?