Yeah, there seems to be mixed feelings about the controller as a whole. That basically says that the controls aren't perfect yet. Rectifying this will be critical to the Wii's success.
That being said, the Wii is the big winner at E3 for me. The 360 and PS3 haven't managed to make me even remotely interested in them. My concern with the Wii, other than the above paragraph, is third-party support re: core gamers. It's probably because it's too soon, but the third-party support seems a bit underwhelming. Namco does a horceracing game, Konami does a Pikmin-type game, Squenix does spin-offs.
The only 'big' third-party title is Red Steel, and even that is somewhat underwhelming. The gun section is nice, but if the controls are worse than WASD/mouse mode, then 'immersion' means squat. The swordfight parts certainly look cool, but it's not even freeform. You have 8 directional attacks. Basically, the Wii is being made a variation of the mouse. It doesn't do anything the mouse can't. Yet.
The 1st-party games sound awesome. Mario Galaxy, Zelda Twilight Princess would be must-buys for me. Yet, their use of the Wiimote is minimal at best. SSBB is my more anticipated game on the title by *far*, yet Wiimote use on it will simply be optional. 1st-party alone won't be able to save the Wii. It needs longer-lasting value. I am not a non-gamer. As cool as Tennis is, it isn't a system-seller.
Where are the big titles? Give me a second Wiimote and give me two guns and just let me ravage everything on screen. No other controller allows me to do that. Halo2's dual-wielding will look like the joke it already is. Give me a second Wiimote and let me chop things up. I want to have an intense sword duel while fending off a multitude of cronies with my gun in my second hand. Make a survival horror. Give me a flashlight in one hand and a gun in the other. If the Wii is all about freeing up my hands, then LET ME make use of those hands. Don't just make the same games with 'different controls'. THEN that just sounds like a gimmick.