Well, from simply easy zooming in ovi maps or in browser to having games with no d-pad, multi-touch is what makes a big difference in usability. I know many people would want to only use mainly the phone capabilities, but also many people want gaming, easy browsing and easy maps navigation.

Then there are applications on iPhone that ppl want them ported to maemo, but they need also UI re-design if for the multi-touch gestures buttons or scroll bars need to occupy the screen for zooming and other things achieved easily with multi-touch.