So far Sony Santa Monica, Media Molecule, and Guerilla Games have all said they're not showing anything at E3 2014. They're all working on multiple unannounced projects, but not showing them yet. Naughty Dog has an unannounced project in the works as well.
We might see something from Sony Bend, Japan Studio, Sony London, Sony Online Studios, Quantic Dream, Polyphony Digital, Guerrilla Cambridge, Foster City Studio, San Diego Studio, Sucker Punch, Pixelopus, etc. They're likely all working on PS4 games.
Stuff that will almost certainly be there:
Naughty Dog trailers for TLOU Remake, Uncharted 4
Ready at Dawn trailer for The Order: 1886
Evolution Studios trailer for DriveClub
From Software trailer for Project Beast rumored
Japan Studio trailer for The Last Guardian rumored
Trailers for Destiny, FF15, Assassin's Creed Unity, and other major AAA 3rd party games.
Indie game sizzle reel that everyone will complain about
Another remake of a PS3 game that everyone will complain about
Sales talk, bragging, 8 million+ PS4s sold
Chances of a new AAA game reveal for 2014 are slim. Driveclub and TLOU Remake are probably the only two 1st party exclusives for the rest of the year. Lots of games in development, but few to reveal at this point.