I'm not fond of the Sixaxis, really, as a controller - it is difficult to make the case that it feels sturdy or exhibits satisfying heft. This thought persisted only a few minutes into my life as an amoeba and then was replaced by a desperate need to traverse fluid and consume other microorganisms. Then an urge to develop longer, more powerful flagellum became my goal - as though an episode of Unique Whips were playing out at the cellular level. So no, I don't like the controller. Playing Flow, the controller seemed to disappear. It makes a case for motion sensing controls that is as potent as anything Nintendo has delivered to date.
That's the parable, I guess. A controller is as good as the game. A system is as good as its library. Far all these interstitial lamentations, all the saber rattling and console war propaganda, there is a simple remedy: a breathtaking exclusive experience. I'm not comfortable saying (as others have) that Flow reaches the high bough we call a "killer app." It's amazing, and you should play it, but it wasn't true when they said it about Geometry Wars and it's no more true now. Will it be Motorstorm? I guess we'll know in a week.
I'm curious. Not nearly $600 curious, but curious nonetheless.