http://www.gameranx.com/updates/id/412/article/killzone-3-unofficially-announced-with-leaked-scans/

It seems like Killzone 3 has been unofficially announced and the latest issue of Gamepro which was acquired by gamespot.com user has a ton of details regarding the game.

Killzone 3 details revealed in the mag:
- Will show the Helghast have humanity left in them.
- Will have the feeling that "of being in a place far away from home, outnumbered by people who want to kill you."
- Will be like Inglorious Basterds.
- All of the characters in the screenshots are flying in.. jetpacks?!
- Will include arctic levels.
- One mission in the game involves rescuing ISA Captain Narville.
- Game is playable in 3D!
- Have to wear 3D glasses, apparently the 3D effects are "crazy."
- Combat is "unchanged from predecessor."
- Or is it? Hand to hand combat involves you "Unloading a string of different (and often brutal) attacks on stunned enemies."
- The scale is supposed to be "bigger this time."
- The Jetpacks are "surprisingly lightweight and agile, Killzone 3's jetpack is easier to maneuver compared to the sluggish incarnations of the gadget found in other games."
- New weapon called the Wasp, basically shoots a "flurry of rockets" at an enemy.
- Will show off the Helgjast culture.
- There is actually a Helghast language, which will be explored in the game.
- Will have "diverse locales."
- Have to sit in the center of the 3D tv for the 3D effects to work.
- 3D in this game is called a "Game Changer."
- Going to have "Intense Action"
- Jetpacks double as a weapon, which basically means a machine gun mounted right on top of it.
- If you shoot Helghast with jetpacks, they'll "explode like roman candles"
- To control the jetpack, you "have to activate bursts of speed in midair, propelling yourself across further distances."

Have to sit in the center of the 3D tv for the 3D effects to work.