Been there today, pretty underwhelming...
For the record, the GC goes until monday so no, the 19th is NOT the "day after the convention".
There weren't as many booths as I thought, only a few publishers, the big three and some organizations that have only little to do with gaming (youth protection, game development university courses, a magazine for pubescent girls that for some reason was promoting the DS).
EA set up shop in the entry hall instead of the exhibition halls (maybe they also had a booth inside one of the halls, I tend to ignore EA). They had a few cars there to advertise some racing game or another, even a "demolished" ferrari to promote Burnout. And of course FIFA 06 but that's not my cup of tea.
The big three:
Microsoft had the smallest floor space out of the Big Three for the XBox, they had a second, albeit small, booth for Windows games but the X360 area was smaller and less interesting than you'd expect from them. There was one big screen where they showed a few trailers presumably of 360 games and a few TVs scattered around that displayed 360 demos (one I saw was DoA 4, the other Kameo, damn, Kameo looked ugly!). Some seating cushions in front of large screens that displayed... something. Dunno, I don't think it was game footage.
The X360 dummies didn't look that huge but they're certainly larger than any console I own. Not that remarkable but not as ugly as Sony's designs so all in all rather passable. The controller didn't look very exciting either, like some poor PC controller.
The music playing when I arrived was Metallica's "My Friend of Misery", when it reached the line "Misery loves company" the EA logo appeared on the big screen, I thought it was funny. Then they started demonstreating Final Fantasy 11 on the X360. When asked "Will that be available at launch?" the representative replied "If you count the beta, yes".
Sony had a pretty big booth. It was fairly open, composed mostly of large seating cushions with PSPs and a few PS2s strewn in. Since the PS2 screens were in the ceiling and the PSPs had no large screens attached you couldn't see any game graphics when you looked at the booth. Way to get me interested. The few PSP screens I looked at were showing some racing games. Not sure how many different ones there were, they all look the same to me. They also had a PSP rental station. I didn't use it, what would I want a PSP for? I think there were also large booths dedicated to the eyetoy.
There was also a long line of PS2s across from Nintendo's booth. Those were standard kiosks as you'd find them in a store. I found a free one that was running Wanda and the Collossus and tried the game out because it's one of the few I was interested in. Urk, big mistake. You start next to a sleeping woman on some kind of altar. The framerate is HORRIBLE. IF that was two digits I'm Caesar! Controls seemed fairly complicated and since I had no freaking clue what I was supposed to do there I tried running around a bit, called my horse (apparently named "Yorda") and rode it to the edge of the temple where it didn't want to continue and I jumped down. Then I was in some area. No clue where to go so I did the thing I usually do: Stop playing the game.
I also looked at the PSP for some time, trying to figure out why people find it appealing or think the screen is any better than that of the Gameboy or any PDA. Had the same cheap plastic toy look as the PS2.
Nintendo's booth was smaller than Sony's expansive booth but jam-packed with demo kiosks. Pretty much any upcoming first party game was there, plus a load of third party ones. I tried getting a DS download signal, interestingly I found somone spreading Jump Superstars but the official demos at the booth were nothing I hadn't seen yet. One section was for the new Zelda. Looked like the old Zelda with new graphics so I didn't bother with it. There was also an area where they demoed Mario Kart DS online.
The first demo I tried was Lost In Blue but I surrendered to the flashing icons and lack of idea what I'm supposed to do fairly quickly. Then came Kirby Power Paintbrush. Went through the tutorial and the beginner level, seemed nice. Next up was Viewtiful Joe Red Hot [something]. It's Smashbros with VJ but with a twist: The mode shown didn't have you fight each other, it gave you goals (stuff like "collect gems", "defeat that boss", etc), the level (a biplane in this case) morphed each time the goal changed and all in all it was pretty different from SSBM's playstyle. The controls felt floaty and the game was REALLY confusing (lost track of my character way too often) but I still managed to win against one human and two AI opponents

. I also tried Nintendogs. Well, tried is the wrong expression, I started the game and looked at the interface for a few moments, then left.
The DS kiosks had screens over them showing the DS's screens so unlike Sony's booth it was fairly easy to see what's running on these units.
There was also a solitary Metroid Prime Hunters E3 2005 DS, the game wouldn't start because noone else joined...
From the booklet they gave out I learned that Prime 3 Arena is scheduled for 2006, that NoE acknowledges the existence of "Play Yan 2" and that there will be a pearl-white GC and Mario Football bundle.
Oh and if you were glad Nintendo didn't advertise Nintendogs with "Who let the dogs out" be glad you weren't here because NoE did JUST THAT. Oh and after that they had Kool Savas, a talentless rapper whose only claim to fame is that he was one of the first in this country to use a lot of profanity and sexual expressions in his "songs". But hey, the MTV demographic love him so I guess it was worth scaring away all the gamers...
Capcom had a ... cube. It was some walled-off cubic room with a big Resident Evil 4 logo on the outside and they only left people in every 15 minutes and only a few of the ones lining up in front. Needless to say I never saw what was inside. They had a big TV above the entrance showing trailers for stuff like Okami and RE Outbreak 2.
Konami's booth was about as large as Microsoft's, they had DSes running Castlevania DoS and a few PSPs for other games (most importantly Metal Gear Acid, of course). A quarter of the booth was dedicated to Pro Evolution Soccer 6, another, closed off*, quarter to some gang game and a tactical shooter.
Konami's booklet told me that they a. will release the next Castlevania 3d for the XBox as well and b. that they don't realize that Soma is Dracula.
The Midway booth had a theatre showing off UT2007. Yeah, like I'm going to stand in line for some promotional videos.
The Deep Silver booth finished showing X3 shortly before I arrived. That was the only game on their list I cared about!
Most booths I ignored because they were displaying racing games, sports games or tactical games (or sometimes booth babes with no mention what game they're promoting. Square Enix had a tiny booth with a few boothbabes dressed up as catgirls). It looked just as uninteresting as retail shelves.
In some hall there was a CS tournament. Well, it was... CS. Can't say it looked any different from amateur CS, it's always aim, shoot, die without knowing where that bullet came from. The commentators were screaming like there was something awesome happening there while all the screen was showing was... CS.
I was surprised at the number of "booths" representing actual sports. The Leipzig Lions, an American Football team had its booth where people could play the sport without proper armor (some would argue that AF without armor constitutes Rugby...), there were a few football booths, 6-vs-6 beach volleyball and some more outlandish ones (bicycle swing, reenactment of Super Monkey Ball)
I probably forgot a lot, if I can remember anything additional I'll add it tomrrow.
*= German youth protection laws make it a criminal offense to let a minor play a game that's rated higher than his age on a kiosk so they gave out bracelets telling your age group (12-15, 16-17, 18-), most people at the show seemed to be 16-17.