OK, so lets take the other 2 next gen consoles.
The 360 like the PS3 are sold mainly on their next gen graphics, if you say that the wii is a gimmick just because most games dont use the wii's unique controles to full effect can we not say the same about the 360 and PS3, its not as if all 360 and PS3 titles are pure Eye candy now are they?
In the first year that the 360 was out, there wasnt a single title that you could realy call next gen, it wasnt untill Gears of War came out that you could and the same will happen for for the PS3, its current line up isnt great by any means.
And the same will happen for the wii, going by nintendos past record with consoles (N64 & Gamecube) you cant realy hold the developers responsible for not jumping on the wii as a viable system can you? now that they have seen it is a viable system more and more developers are now making games (Sometimes EXCLUSIVES) for the system and it will take time for then to make full use of the wii's unique controlers.
Is the wii a gimmick with its revolutionary controllers? Hell no, just like the mouse or joypad wasnt.
Give it time people, give it time. Its only been a year.
My prediction is this:
In as little as 5 years time nobody will be playing FPS games with a joypad or even mouse + keyboard, considdering how neer perfect MP3's controlls are why would you want to? and if your answer is that you cant get used to them or you dont like them then just think back to your first games using either of the 2 alternatives.
Developers are now starting to develope games for the wii from the ground up, this means more time spent on making the controlls work, this can only be a good thing and will probably weed out most of the games with badly implemented control systems.