CLOVERFIELD or 1-18-08... what else do we know?
IGN has lots of good info. They even tracked down the owner of some of the viral websites that may be pushing more info on the movie.
Ain'titcoolnews has more info on the director and stuff.
A supposed claim of some poster to have survived the attack in IMDB, which sounds so much more like a wannabe hoaxer so no links here.

Some key lines in the trailer:
"Going to Japan."
"Saw it.. it's a lion.. its huge..."

35 minutes from first and second picture.

Makes you wonder eh?