They might've, but since Miyamoto made the comment that you could substitute a 3DS for a uMote, the fact that they didn't just come out and say it was multi-touch, and that none of the software/demo's at E3 supported multi-touch would lead you to assume that there was only a single touch resistive touch screen in the uMote at the time of unveiling.
I know the patent states that it can be single, multi, resistive or capacitive, but I'm just hoping Nintendo decides to lean towards added potential over the saving of a few more $$ when it comes down to cost considerations and feature compromises.