I'm really interested in the WiiU of course, as it looks like Nintendo have finally pulled their heads out of their ass after many years of "it's our way of thinking, or no way" attitude. I'm very much looking forward to see how they put their own spin to online gaming and communications. I've read that they are finally adding some form of trophy/acheivment support. Now I know many don't care for this, but many do, and I'm glad to see "N" doing what is required to bring in support from other console fans.
The only real 3DS news I would like to see is a redesigned 3DS(Bigger screen & sweet spot, with a second nub thrown in). I doubt this will happen, as the 3DS hasn't been out to long, but I can dream. I would also like to see some firm release dates for Animal Crossing, Luigis Mansion 2, ect.
I'm sure the PS3 and 360 will have a solid lineup, but since they are both nearing the end of their life cycles, I really don't expect to many great announcements, as most new killer games will be held over for the next gen(but there may be a few suprises). It would also be nice to see Sony show some more MOVE support, as it seems like they have already given up on it. I would also like to see Microsoft be more into to real games and less Kinect crap.
Last, but not least is the Vita. This E3 is really do or die for Sony's new handheld. They really need to announce some new killer ip's and apps, along with firm release dates. A price drop would be nice, but I think they should hold off on that until closer to the holidays. I do expect them to announce some kind of price drop for memory though, along with some bigger sizes(maybe a 64gb card). I'm also sure they will announce some bundle packages that include system, a game, and a memory card for a set price. They may even announce some new colors to go along with the bundles.
So I'm most interested in the WiiU and Vita, so I hope they both have good showings and Sony and Nintendo can deliver the goods.
Chris