We got a leaked (possible) plot synopsis for Ridley Scott‘s Prometheus yesterday, which was followed by Fox “coincidentally” releasing an official, infinitely more vague one last night. Luckily for those who want to keep tabs on the movie, but don’t want to be spoiled in any way, some new, small information has come to light on the Alien prequel.

JoBlo says that Alpha Dog and The Mechanic actor Ben Foster has joined the cast in an unspecified part, one that will put him alongside people like Noomi Rapace, Michael Fassbender, Charlize Theron, and Idris Elba; not bad company by any stretch of the imagination. As JoBlo pointed out (and as my feeble mind has already forgotten), Foster had a leading role in the Alien-inspired thriller Pandorum, which means that he should be prepared for getting terrorized aboard a spaceship. He’s a talented actor who doesn’t get quite as much work or attention as he may deserve, but it’s hard to argue that being put in this movie is bad for his career. Prometheus will open on June 8th, 2012.

In other sci-fi casting, THR has learned that Vince Vaughn is in talks to join Ben Stiller in the Seth Rogen & Evan Goldberg-scripted Neighborhood Watch. Set to be directed by Akiva Schaffer, the movie stars Stiller as a “newcomer to the neighborhood whose idea to join the neighborhood watch to get socially acclimated goes awry when aliens get involved.” THR expands things further by saying that it “serves as a front for dads to get some male-bonding time away from their families,” and they “get in over their head” when they learn of the plot to destroy Earth.

The two actors appeared together in both Starsky & Hutch and Dodgeball back in 2004, while they also had cameos in Anchorman. I think there’s a lot of promise in the combination of the basic plot and the writing team behind it, so this is the first Ben Stiller movie that I’ve been looking forward to in quite some time. Vaughn is someone who I think can be a good comedic performer, but the material he’s given really makes or breaks his presence in a movie; maybe this can do him some favors. The two of them have a good chemistry onscreen, so them working on this together might be a nice sign for the film.

Do you think Foster is a good fit for Prometheus? Is Vaughn and Stiller reuniting something that you have any excitement over?