Of course, they are closing their mouths the same way Nintendo is doing. For sure they have got BIG things to unveil, just remember last year when they showed Final Fantasy XIII for xbox 360.
Games that may be unveiled: Forza 3, Killer Instinct 3, Alan Wake, Halo ODST, Splinter Cell Conviction....In fact, they have as much as Sony, but Sony need to create more hype because they are currently in the last position.
I think all three companies will have a great show (at least, I hope)







