Apparently, Ain't It Cool News got its hands on a Jurassic Park 4 script written by William Monahan and John Sayles. Monahan is some young and upcoming writer who has three films in production. Sayles is the master independent filmmaker, but this is more in line with his early work on "Alligator" and "The Howling."
From the review, it sounds like the script veres off into really unexpected territory:
There’s the eight-year-old-boy side of me that thinks that a DIRTY DOZEN-style mercenary team of hyper-smart dinosaurs in body armor killing drug dealers and rescuing kidnapped children will be impossible to resist. And then there’s the side of me that says... WHAT THE FUCK ARE YOU TALKING ABOUT?!
If there's any truth behind this thing, it could really be fascinating (or just screwed up), but it doesn't seem likely that Hollywood is going to produce it anyway. We'll have to wait and see.