I've had a DS now for a number of years, as have many people, and I observe that I've done an enormous number of things with it that would not have been possible with my big fingers. To the extent nobody sees a use for styli, is that because they are really useless, or because right now every program you use has been optimized for the fact that you're just sort of jabbing at the screen?

By no means should a cell phone require one, but there are vistas opened by styli that we may want to explore after the novelty of "holy cow, tablets! they finally work!" has worn off.