Sony's Battle: Los Angeles comes out in March and they want to make sure that everyone who's susceptible to any movie marketing that includes the destruction of major cities by outer space aliens knows what's coming.
If the trailer gets you jacked up, you can visit their website to play a FPS online game called Unknown Enemy.
Since they had to use computer imaging to blow up L.A. anyway, the studio saved some cash by using some Louisiana tax credits to film in Baton Rouge and Shreveport. The sometimes-reliable Wikipedia reports that Second Battalion, First Marines sent personnel to the shoots and that additional scenes were filmed at Camp Pendleton. Let us know if you were there or know someone who participated in the shoot.