E3 Ultimate Game List

1UP has the E3 2006: Giant Game List up now. Some standout titles include:

Sony

Call of Duty 3 (PS3)
Oblivion (PS3)
Turok Next (PS3)
Madden 2007 (PS3)
Metal Gear Solid 4 (PS3)
Unreal Tournament 2007 (PS3)
Final Fantasy XIII (PS3)
Tekken 6 (PS3)
NCAA Football 2007 (PS2)
God of War 2 (PS2)
Mortal Kombat: Armageddon (PS2)
Final Fantasy XII (PS2)
Oblivion (PSP)
Lumines 2 (PSP)

Nintendo

The Legend of Zelda (Wii)
Super Smash Bros. (Wii)
Metroid Prime 3 (Wii)
Madden 2007 (Wii)
Red Steel (Wii)
Castlevania: Portrait of Ruin (DS)
Final Fantasy 3 (DS)

Microsoft

Fable 2 (360)
Madden 2007 (360)
F.E.A.R. (360)
NCAA Football 2007 (Xbox)
Mortal Kombat: Armageddon (Xbox)
PC

Neverwinter Nights 2
World of Warcraft: The Burning Crusade
Unreal Tournament 2007
Half-Life 2: Episode 1

Don't consider this the end-all list for games at E3 because I noticed a few big titles missing from the list including Legend of Zelda: Twilight Princess and Phantom Hourglass. It does give you a good idea of what to expect on the showfloor though.