Classic.
1. Sony/MSoft wants publishers/developers to make games that show off this new technology so that people will want to buy it.
2. Publishers/Developers don't want to spend the money to develop games centered around this technology until they're sure it's going to be widespread enough to be worth the investment.
3. Developers will create games that CAN use the new motion controls, but also work fine without them, in order to reach a broader market. This will be true of nearly all major games, as they'll really want to reach both halves of the audience.
4. The overwhelming majority of gamers will stick with normal controllers because they work just fine with all the newest and best games.
5. The motion-controlled gaming market will mostly consist of antiquated novelty items (party games, etc) or fitness-oriented software--the few things you just can't get done with normal controllers.
And, if you were to read the above again, but say 3 years ago, we'd be talking about exactly what has happened with the Wii. Way to "innovate," guys.
EDIT: Oh, I did forget one major difference--with the Wii, a couple hundred bucks got you the motion controls AND your console (which could be used with normal controllers from Day One). The other guys are asking people to spend over a hundred bucks IN ADDITION to the hundreds spent on the console itself...
And, since these casual-friendly games usually draw folks that aren't interested in shelling out a large percentage of their income for these games... Wii wins on price long before PS3/X360 win on graphics.