The rumors are true! The next trailer for Cloverfield WILL be shown before Beowulf.
Officially, the release date for Beowulf is Friday, but many theaters will be showing it Thursday around 9:00 pm, and some theaters will be showing it in 3D.
Alex at FirstShowing.net has already seen the new Cloverfield trailer, and has a pretty thorough description, including the official title of the movie - CLOVERFIELD.
Alex thinks the trailer will be available on Monday (I assume on Apple.com).
*Thanks to Bradley for emailing me about the clip on YouTube.