IMHO, if the control is part of the gameplay inherently (like flOw), then it should be left alone for the users to experience. But if the control is simply a mechanic to get to the game objectives (like sports or fighting games), I believe they should provide the easiest control for all to use effectively. It's no longer an experience or an art. As long as these control options are easily accessible (e.g., 2-3 quick choices), then we should be fine.
All these talks are making me impatient. 2 weeks is very long, isn't it ?
EDIT: Here's a gameplay footage (showing SIXAXIS also) in Taipei:
http://n4g.com/ps3/NewsCom-55408.aspx#Comments
The player looks engrossed in the game, which is good. Too bad no one interviewed him.