Yes, this does look cool. The fact that you can do it on a handheld definately is a plus.
However it's not THAT special from a musician's point of view (I'm an enthusiastic amateur musician myself) because it's basically just a software synth with it's only limitation the hardware that it's running on. A DS is definitely strong enough to support such a synth.
I do love the fact that they've bothered to make the touchscreen of the DS into a KAOSS pad (which exists as a seperate little device from KORG aswell)
But I think this will appeal more on gamers who are not into music(-making) because it's like a whole new world opening for them; while a musician-gamer will already know this type of software exists.
But the idea of doing it for a handheld alone is worth applause for KORG!
(I'm more of a Yamaha guy though
)
Decided to just quote Sirgin as what he said pretty much hit the nail on the head.
There is already a lot of music software out there, some worse, some better, some even free.
The real icing on the cake is its portability. It is even more portable that a MacBook Air on a DS