If there's a number in a film title you've got a sequel, right? Not necessarily, unless Oceans 1 through Oceans 10 came out on some obscure underground label I've never heard of. The trailers are getting all mathematical on our collective ass this week, and each of them (sort of) sports a number in the title.

Four Christmases
It happens every year. The first time I see a sign of the coming holiday season I cringe. I like Christmas fine once it gets here, but being forced to think about it in September is asking too much. Anyway, this is actually a TV spot, which is appropriate since it sounds like the plot was lifted from a sitcom.Vince Vaughn and Reese Witherspoon are playing a couple who, thanks to a canceled flight to Fiji, are forced to visit all four of their divorced parents on Christmas Day. Pretty wacky, huh? This flimsy plot is being held up by an impressive cast which includes Mary Steenburgen, Robert Duval and Sissy Spacek ... but I doubt that will be enough. Note: Link above now pointing to new full-length trailer.

Terminator: Salvation
OK, there's actually no number in this title, but we're all mentally planting a "4" after the word Terminator. After Terminator 3 I really didn't care if the series lived or died. Without James Cameron at the helm and Linda Hamilton in the lead we were left with mindless action and none of the compelling elements from the first two films. This is only a teaser, but with Christian Bale taking over the role of John Connor, I'm thinking there may be hope. We get a glimpse of a post-apocalyptic future, and Connor tells us via narration that this is not the future his mother warned him about. Considering how bleak that future was portrayed in the previous films, it's chilling to imagine how it could get worse.