Scream 4, as the poster says, will introduce new rules to follow in order to survive a horror movie. The movie is set to start filming soon and will be released April 15, 2011.
Wes Craven will be returning to direct (he directed the first three films) and Kevin Williamson will return as the writer. Williamson wrote Scream and Scream 2, he didn't write Scream 3 (which wasn't great).
There is a lot of plots I've read about, but I won't post any of them until I know which one is real. I do know that they want to make a brand new trilogy, with new characters and storylines. So, if this one is a success you should look for Scream 5 and Scream 6 to follow.
Courtney Cox, Neve Campbell and David Arquette will be coming back to reprise their roles. They are the only cast members confirmed at this time.
I'm a huge fan of the Scream films. The original Scream is one of my favorite horror movies of all-time and I'm excited to see the franchise coming back. Hey, Wes Craven I'll be in the movie and I'll work for free.