The people who are pissed are people who wanted Nintendo to repeat Sony's conference, or were totally suckered by Nighttrain. Nintendo's conference won't generate too much hype, but their was nothing fatally wrong with it either. All of the conferences had their highs and lows.
Microsoft's was by far the worst. They put all their cards on the table and only came up with a small pair. The Xbox is now basically dead and the Xbox 360 will be branded as the Xbox 1.5 for a long, long time. This was more than just E3 for MS, it was the Xbox 1.5's unveiling, this will hurt.
Sony's conference was pure hype. Which is good for the PS3, but bad for the PS2 and PSP. Those two systems we're practiaclly ignored. I honestly don't understand why Sony choose the presentation they did. The PS2 may not need a boost, but the PSP does... and it needs it now. There is still plenty of time to hype the PS3, but time is running out on the PSP. Sony delievered a serious blow to MS in the console race, but hurt themselves in the handheld race.
Nintendo's conference was okay. Johnny got to me too (he has some explaining to do), but with 4 platforms to balance I wasn't expecting that much Revolution info either. Too much Nintendogs, but after its success in Japan I'm betting that they have some big plans for it worldwide. The DS stuff look great, as did the Gamecube stuff. Really, the only thing missing that I hoped would be there were some Rev teaser trailers, other than that it was fairly well balanced, with alot of information... just lacking hype. Nintendo really sucks at hype.
People claim that E3 doesn't really mean much, and they're right. 2003 was Nintendo's worst E3, but their best sales followed that year, 2004 was their best E3, but some of their worst sales followed. The next-gen is just beginning, there will be plenty of time for everybody to screw-up, dissappoint, and piss people off.