I'm surprised Demi didn't make this thread already. Maybe the E3 excitement is too much for him. I played a little and here are early impressions:
It's Kingdom Hearts on the DS. It plays really faithfully to the console ones and the only thing you miss is camera control. You can hit select and move the camera or slide the touchscreen to spin the camera or what you actually just use is tapping R to center the camera while playing.
The graphics are amazing. Square Enix continually impress visually with every major release. It looks like KH2 except obviously the geometry is more simple and the textures/models lower quality, but they do a good job at making the areas look and sound real close to the PS2.
Story seems solid. Full on nomura epic stylish drama with twists and turns and cool looking dudes. The biggest flaw here is THEY RAN OUT OF SPACE #$%@%^@^^@. Nomura mentions that since all the cutscenes are big space wasting fmvs with ps2 graphics and full voice, they ran out of space and had to cut a bunch including scenes that were in the story trailers. This means the majority of the game is told through non-voiced text bubbles, boo. It's ok, but I'd rather they had not gone the fmv route and just done full voice with DS graphics for all the story stuff. Luckily in the same interview Nomura said he won't have the same problem with KH PSP because UMD >>>> DS cart.
So yeah, if you love Nomura & love Kingdom Hearts you will probably love this. I think that rules out every poster here except me since I think Nomura is one of the best game designer/artist/director/plot_writer in the industry and I loved KH & KH2 except the last 1/4th where it fell flat and had a weak ending.