In my town's MediaWorld it's the game with the 3rd largest shelf space, with WoW and FIFA being 1st and 2nd respectively. Toddlers and little kids like it, but I never saw elder kids interested in and trying it on the demo PS3. But it looks like it has its niche, and games of the same kind, but less simplistic, could enjoy a comfortable success niche also with a more grown up public.
Anyway Sony should have made the navigation control a standard equipment of every PS Move kit, to make its use always possible and push its SW support whenever suitable and not bound to its smaller user base, as from what I saw, free roaming, not on-rails games will require either it or a clever way to implement navigation through motion detection of any suitable part of the rest of the body except the hand and arm holding the wand.