UPDATING WITH RESULTSI don't think we'll get any Pokémon information, at least in regards to BW2. If I recall correctly - at least from what I can remember first hand - Nintendo hasn't had a main series Pokémon game at E3 since Fire Red/Leaf Green, and that was only to show off the wireless link attachment.
Here's what I'm hoping for outta this year's E3 from the big 3:
Microsoft:
Dance Central 3
CORRECTA new Alan Wake game
FAILUh... hrm. Using Rare to make good games again?
FAILSony:
Limited edition Vita with DJMax TUNE!!!!!!!!!! I'd buy it even though I already have a Vita
FAILAdding Shepard or Kaidan or Garrus into their Smash Bros. clone (if Big Daddy can be in it, why not?)
FAILThe announcement of PS1 classics working on the Vita, and adding a ton more PS2 classics (that would also work with the Vita)
MOSTLY CORRECTLast Guardian release date/cancellation announcement. I'll take either one at this point because I'm sick of waiting
FAILLumines ES sequel for Vita with DLC
FAILA new Jumping Flash game and/or Robbit in their Smash Bros clone
FAILA sequel to Fantavision even though I'm the only one that loved that game
FAILA new Quantic Dream game, hopefully based off the Kara demo
MOSTLY CORRECTNintendo:
Wii U pricing, release date, and COLORS
Glimpse at the new Smash Bros. games, since it can't be far in development, if it's even been started
New Metroid game for Wii U and 3DS
New F-Zero game for Wii U and 3DS
Release date for Fire Emblem 3DS and that awesome Cobalt Blue 3DS with the game bundle that Japan got coming to the US
DJ Hero 3DS making a triumphant reappearance despite series cancellation
As much as I don't really want it to happen, a 3DS redesign to make the system feel a bit more comfortable to hold... and maybe a bit bigger screen and second circle pad
I think I'm maybe expecting... 1 or 2 of those things on my list to happen. Nothing else.