I think Waggle is soo prevalent for three reasons: Developers think very little of casual gamers and assume they can't properly execute complex motions or gestures. The Wii isn't as responsive or as precise as they like. Their too stupid or simply to lazy too think up any realistic or at least creative ways to command on screen characters.
If properly executed and advertised (illustrate how different and superior the Move is to a Wii mote), Sony could beat Nintendo in the VERY long run. After all, Nintendo drops their consoles like a bad habit once a new system launches (N64,GC), while Sony dukes it out for at least a decade. Nintendo isn't gonna be pushing the wii in 2012, they'll be too busy trying to convince the casuals to upgrade or evolve (knowing Nintendo).