There is one (or maybe 2) tablets that can use either input system. They're fairly small-market devices, primarily for rugged use. Check out the current (or last?) issue of Pen Computing? magazine. (I apologize, I don't have it available. If I get a chance to find it, I'll post more details). The one reviewed had 2 digitizers and you could select which input method you wanted - Wacom or inert stylus. A specialty device to be sure, but in general it's one or the other, and only Wacom style on true Tablet PCs.