Hahaha, no. The penetration itself doesn't have anything to do what I think about the device. You have yet to draw the business plan how you can get 70% adoption rate by releasing it in the third year. The reason you didn't answer me this question should be obvious.
Again, it has nothing to do with the potential because I'm pretty sure that it will be mandatory in the next gen. More over, I clearly show that the circumstances make your assumption of having a ridiculous adoption rate difficult.
Let's look it this way: I love the touchscreen of the DS, I like waggle and pointing. However, that doesn't mean every DS game needs touchscreen function, or every Wii game needs waggle and pointing (to demand such a thing is rather fanboy warz).
Some games might be better with M+, though I don't see why the majority of the games should need the device. That said, I can see developers adding some funny features as a selling point.