According to THR, the Scream 4 script is currently at 140 pages.  While things change all the time on set and in the editing room, 140 pages for a horror movie is very unusual.  The thing you need to know is...one page usually equals one minute of screen time.  If you do the math, Scream 4 could end up being close to a two and a half hour movie.  But it's probably going to get cut down in the editing room, as the first three films were all around two hours.

Also, in the same report, the film was supposed to wrap around Labor Day, but production is now scheduled to go till September 24.  While adding days to a production is nothing new, as you can tell when reading all our coverage on the making of Scream 4, the film has dealt with more than a few bumps in the road.  Saying that, no matter what the film costs and no matter how long the film ends up being, it'll probably open huge and make back all its money in the first few weeks.