According to Nomura's interview those aren't precisely Coded's graphics, they're actually a computer representation of what they HOPE they'll be able to put on Cell phone hardware, but as of now there is no actual in-game footage because they don't even know how far graphically they can take the game
You can't really be so judgmental of 358/2's graphics that we've seen so far for a couple reasons
1. Because these are very early-in-development screens of the game
2. Certain graphical styles look fantastic when in-motion during play, but if you try and take a still-screen of the action, they end up looking terrible, when really they look great when it's in motion
3. The scans we have are actually enlarged and distorted slightly from the DS's screen resolution, meaning that these images are actually slightly pixelated from what the graphics actually look like because they enlarged them for the scans
Also, from what Nomura's said so far, Coded is actually 2D sprites rendered on a 3D map, meaning that Sora and co. and all the enemies are actually 2D, but the background like Traverse town and the Blocks are rendered in 3D
Whereas the DS game is completely in 3D