For those of you wondering about Kojima's opinion on the Nintendo DS...
Metroid Prime 2: Echoes Game Informer
"The fact that it comes with two monitors and the touch sensor, and you can tell that it's a Nintendo product, I think it's a good thing, and I think you could do many things with it. The two screens and touch sensor feature are the draw of the thing, and I think that when many developers start developing games for the DS they will be focusing on these features. The thing is, when people do this, they'll be coming up with the same game ideas, and they'll be too simple. What I would like to do is something no one else would think of."
Hideo Kojima
So will we see a Kojima game on the Nintendo DS? Judging from this assessment from the man, I would say eventually.