I want you to go watch the KH3D trailer in HD. It looks awesome; the models are more polished than KH2's, and it's much more round. The only thing putting a KH game on NGP (or PS3, for the matter) would do is make them more round. Not really a valid reason to spend the time of creating brand new models.
I voted for PS3 because it had 0 votes. I don't really care what the game goes on, if the game even exists.
When you say "watch it in HD," I certainly hope you don't mean "blow the video up to full-screen" because it looks hideous like that. x_x
The biggest advantage the NGP has isn't the ability to render more polygons -- it's the ability to render polygon edges with pristine image quality due to high pixel density, very cheap 2x anti-aliasing, and a presumably-absurd amount of RAM. It would be a pretty stark comparison to KH

DD, which has great texture quality that's brought way down by jagged edges near every distinct edge on screen.
As for why this frustrates me so much compare
DDD with BbS.
While DDD clearly has better character models, the jagged edges detract from the overall quality more on the significantly-more powerful 3DS =/ (Note that I'm using direct-feed images from both rather than the enhanced screens Square-Enix releases -- and for DDD, that means resizing from the video, because there are no unenhanced stills; this probably benefits DDD if anything, because the resizing algorithm likes things to be smooth)