This year Nintendo will announce Wii Fart ...and win again.
Now seriously ,the impression of last year was a SOny win ...but looking it from now it doesnt look like it as the Wii has sold much more etc.
And as for this year I think MS has announced everything they got to counter MGSIV this week.They will push heavy on Tales of Vesperia ,Infinite Undiscovery ,the temporal exclusives as SO4 and Last Remnant(although the later one could be weeks we dont know),plus Fable 2,Too Human (if its good enough) ,Halo Wars ...
As for Sony ....I dont know.They have lots of product to show ,but they must show lots of new things if they want to impress.The last two weeks have been very bad ,with the development of three games halted (Red Alert ,8 Days ,Getaway)and the news that Last Remnant will come later and SO4 will come later too if it comes at all.Nothing short of showing at least 5-6 new potentially AAA games will impress after that.
They of course have Wipeout HD ,Socom Confrontation ,Little Big Planet ,Resistence 2 ,Killzone 2 ,White Knight Story and Motorstorm 2 ,plus others as Buzz ,Infamous etc ....but they have to show new things.They will of course use the Bioshock card,and In-Game XMB and Home if they are able to ,but if they dont show at least 5 new games I will be dissappointed.