E3 was awful this year overall. Ubisoft had the best conference, with Sony second, but the other three were horribly mediocre. There were no surprises, no big announcements, and 95% of everything shown was a shooter or milked sequel (or both!). Watch Dogs was very impressive, and as a fan of the series AC3 looks really good, but other than that I can't say I was happy at all with E3.
My main complaint about Sony was the lack of Vita (seriously...the thing has so much potential, sales are abysmal, and this was your chance to show some kickass games to make it worth buying - not just spend about 5 minutes on it) and the overly long/boring/stupid demonstration of Wonderbook (again, this could have gone to Vita discussion). Other than that, they concentrated on showing off games, which is what E3 is all about, so overall they had a fairly solid conference with a few missteps.
Nintendo especially should have kicked ass this year, but their conference pretty much boiled down to "We love you, core gamers! Now here are some ports, Wii Fit, and a minigame collection, and you'll damn well like it!" Between the conference and the 3DS showcase, Nintendo actually killed any hype I had for the Wii U or any of the upcoming games. Seriously? Paper Mario is built around one-use stickers that you need in order to even do basic battle commands...and you don't even get anything for doing battles since EXP comes from being slave to random Toads? And not one, but TWO generic NSMB snoozefests? But oh wait, NSMB2 has gold! Shiny! Never mind the fact that it's still bland and uninspired - and even looks EXACTLY like NSMB on DS. And then they save the big hyped reveal at the end of the conference for...a horrible-looking minigame collection. Pitiful.
And I've learned to just accept that post-Kinect Microsoft will never have a good conference again even though the 360 is my favorite current-gen system.
And most everything shown off has a 2013 release date. 2012 is really shaping up to be a pretty mediocre year for gaming in general. Very, very disappointed in E3 this year.