If you take in consideration that every marketed product is in some shape or form, a gimmick, as with every marketing strategy attempts to appeal to the consumer in hopes of generating sales. The PS3 uses Blu-Ray/Latest Tech, 360 is pushing latest technology as well, and of course that little Wii is boasting innovative controls. In reality it's all a gimmick if you sum it up.
I see your point, and understand that you seem to be saying that a lot of titles and the console in general seems to sell more on promise than it does on product. That is true to some extent when you look at so many developers late in the game and even some that are early, all frantically pushing out just about anything in hopes of delivering a paycheck. With that in mind, so many crap ports and crappy titles have managed to make it's way onto the system.
Despite that the sheer numbers of trash for the Wii is hard not to notice, but really crappy ports and titles are nothing new to a Nintendo console. Look at the classic NES for example, with games like Fester's Quest and so many others that was nothing less than terrible. Other popular consoles have had there fair share, ranging from Atari to PS2 however it's those few good ones that help hide such a wide selection of junk. Unfortunately the Wii still requires more worthwhile games to it's collection to render it's trash list out of the spotlight, so keep in mind the system is still new.
It is fortunate for the Wii developers that it shares the same basic development scheme as it's predecessor, which makes it easier to push forth good games faster as there is less need to re-learn the development technics to make the best use of the system. The downside to this is that last-gen the Cube was mostly overlooked so therefore there still is a learning curve involved as I don't believe that 3rd party developers even took full advantage of the Cube's potential. Now that the GameCube/Wii now has some serious attention, developers are attempting to come up with some killer apps to really cash in on the system. To do this it will take more than a quick port, and developers are going to have to really push the envelope when it comes to maximizing the Wii's hardware and frankly to see the Wii's full potential it's going to take time.
Games like MySims may seem like it's really pushing the console, however if that title was released two years from now after developers master the hardware potential (ie. better optimized code), what we would probably find is that the game wasting more than it's actually using. A good example of this is comparing the differences between games such as Super Mario Bros. and Super Mario Bros. 3 on the classic NES, clearly a HUGE difference. I merely suggest being patient and wait to see the outcome for yourself.