I live near a town where they're shooting tons of extras scenes -- apparently, from a friend who was actually involved, it's "going to be so, so awesome!" She got to run screaming towards a tugboat on the river -- a tugboat which, apparently, Tom Cruise was actually on.
I don't know much more, except for the fact that everybody's been going crazy over Tom Cruise (my roommate's friend, who is an extra, got to shake his hand.)