I'm at the show floor right now, and I have to tell ya, PSP presentation was pretty damn impressive as a hardware, and DS's was just downright pathetic.
PSP had several real time tech demoes including a version of the rubber duck in sink demo used when PS2 debued. The lighting, the rippling of the water, geometry of the objects, they were all pretty damn good. Another demo had a model of a planet that you can change the lighting and change the surface from desert planet to a "green" one with water. This one featured perrty good bumpmapping (not DOT3, which was stressed by the demo guy). Another had a character running, jumping, and rolling in a tube of a cavern, and another had a simply shaded virtual city scape that you can change the lighting etc..
And then on the other side of the demo area were actual game engines being demoed. Most were just rolling demoes, but some you could interact with in limited amounts. These looks to me about really early DC game level in geometry and shading. Interesting thing that I noticed was that all of these game engine demoes were running in 16bit color output, where as the tech demoes were running in 24bit color, so dithering was pretty evident. Still, not bad and again about equivilent to what early DC games were doing.
Game engine demoes I can recall are Ape Escape (pretty close to PS2 version in overall feel), MGS Acid (X-COM style turn based game), a hockey and soccer games (not quite DC level in geometry for the players), Tony Hawk game (looks similar to the version demoed for the MBX), Spider man game (think PS1 with PS2FXs), and a 2D traditional JP RPG (ironically the most interactive/playable of the demoes). That's a lot of freakin games demoing!
Physically, the unit is extremely well designed and put together. And that analog slider pad is pretty damn effective. I was impressed with the execution of the analog "slider" espect. Very space efficient.
The guys there were totally mum on the price though, and from looking at the thing first hand, I have no doubt that this thing will be at least $299. Some attendees were nodding their head at $399 without much rebuttal. And they were also very cagy about battery life as well. No one wanted to suggest anything solid, except to say that it's somewhere between 2.5 ~ 10 quoted by Sony.
As for DS, I'm depressed just to talk about it. Let's just say that I was gonna get the DS to replace my SP I had "lost" before today, and after looking at it and playing with it in person, I'm just going to get SP now. No way in hell I'm carrying that ugly thing in public. It's freaking HUGE for no reason to boot! Makes PSP look positively slim. The pre-hands on presentation with the skanky twin MCs (get it? twins? Two screens? X_X) didn't help matters, nor the incredibly cheesy video of executive acting mildly retarded playing with DS and messaging eachother. WTF? Execs are gonna leave their Palm pilots and PPCs at home and use DS in their workplace? PURLEEEZE!!!!
The unit itself is ugly, and uncomfortable. The shoulder buttons are now just two tiny orange circles, and are difficult to find without looking, and very uncomfortable to use. The face buttons are the size of a gnat's testicles, and if you have fat fingers, forgetaboutit. The passive digitiser in place of a analog pad is just stupid, and I don't think the gimmiky use of the digitiser is gonna advance gaming in the long run. It didn't help PDA gaming at all for instance.
The rendered images on screen was definitely sub N64. No ifs ands or buts. Some interesting FXs were pulled off in software (like chrome and specular shading), but don't mistake this for a decent 3D unit. It's ugly.
Overall, really dissapointed with the DS. Even more than I'd imagined I'd be.