Only just saw this thread today and since I have had some time to spend on the Wii as well, thought I'd share my view as well.
Sadly, I find myself quite in agreement with DemoCoder and agree with most points brought up by Joshua Luna as well.
The games I've played so far are all from Wii Sports game package. From what I noticed, most games are quite "dumbed" down and the level of interactivity that I expected from the unique controller have been left out. If most Wii games turn out to be nothing more than dumbed down Xbox/PS3 games where most actions are mapped to movement, I'd rather take the former. I'm aware that the majority of Wii owners probably see this a little different and that's fine by me - it just isn't my thing. As I've said before - I'd rather spend my gaming time relaxing on the couch using only my thumbs and fingers to be immersed into a game, than using exagerated movements to achieve the same result. Playing dumbed down games (like the Tennis games that's more about the movement of the controller and timing and excludes the strategic running/positioning of the player) isn't immersive either - which ironically is what I thought was the entire point behind the Wii controller (or at least, what was always used as an argument in Wii topics).
Sadly, it just isn't. This of course makes it the perfect mainstream party console for many (which is also why it's selling so well I assume), which is great for them if they get the enjoyment out of it.
Ultimately, this also means that I don't see myself buying a Wii either, despite having said in the past that I see it as that perfect 2nd console. The truth is though, I think I've had more enjoyment from the PS3's sixaxis controller in simplified downloadable games/demos such as the Rubber Duck demo as a party feature than the Wii is worth my money. I may change my mind, but for now, that's just how I feel.
Given how Wii is always brought up as the most successfull console (and being actively compared to PS3 and Xbox360 in sales), I do hope that Sony and Microsoft don't follow suit or the gaming I enjoy, I'm sure will have died for me.