Be aware that, while all these titles are currently confirmed, the occasional developer can't finish an E3 demo and as a result a game could drop off at the last minute. Also, more titles like Take Two and Rockstar's Grand Theft Auto IV will most likely be shown, but have not been confirmed to have an E3 showing. Regardless, here are all PlayStation 3 titles confirmed to be shown in some way, shape or form at this year's E3.

2K Sports
* All-Pro Football 2K8
* NBA 2K8
* NHL 2K8

Capcom Entertainment
* Devil May Cry 4
* Rocketmen: Axis of Evil
* Super Puzzle Fighter II Turbo HD Remix
* Super Street Fighter II Turbo HD Remix
* Talisman

Codemasters
* Clive Barker's Jericho
* DiRT
* Rise of the Argonauts
* Turning Point: Fall of Liberty

D3 Publisher
* Dark Sector

Disney Interactive Studios
* Turok

Electronic Arts
* Army of Two
* Madden NFL 08
* Medal of Honor Airborne
* Mercenaries 2: World in Flames
* NASCAR 08
* NBA Live 08
* NCAA Football 08
* Need for Speed ProStreet
* The Orange Box
* Skate
* Tiger Woods PGA Tour 08

Gamecock
* Hail to the Chimp (confirmed for "next-gen consoles")

id Software
* id Tech 5 Project

LucasArts
* Fracture
* LEGO Star Wars: The Complete Saga
* Star Wars: The Force Unleashed

Midway Games
* Blacksite: Area 51
* John Woo Presents Stranglehold
* Unreal Tournament 3

SEGA
* Condemned 2: Bloodshot

Sierra Entertainment
* TimeShift

Sony Computer Entertainment
* The Eye of Judgment
* Folklore
* Heavenly Sword
* Home
* Killzone 2
* Lair
* LittleBigPlanet
* NBA '08
* Pain
* Ratchet and Clank Future: Tools of Destruction
* SingStar
* SOCOM Confrontation
* Uncharted: Drake's Fortune
* Warhawk

Sony Online Entertainment
* The Agency
* High Stakes on the Vegas Strip: Poker Edition

Warner Bros. Interactive
* F.E.A.R. Sequel

Source: PlayStation Forums