According to Variety, Fox has won rights to all 16 of the Scarpetta books, and is eying it as a potential franchise along the lines of the Jason Bourne films. They're developing the first thriller now, which won't be tied to any one book, but will probably cherry-pick out of all Scarpetta's gruesome cases. The plan has met with approval from Cornwell, who discussed the idea personally with Jolie and her manager, Geyer Kosinski before handing over the rights.
I'm not an avid reader of Cornwell's books, but Jolie seems like a good fit for the sophisticated Scarpetta. While the coloring's different, Scarpetta's a workaholic who dresses well, drives a Mercedes, attracts handsome guys, and handmakes Italian food. She's kind of perfect, just like Jolie. But hardcore fans (and I know they're out there) may have other ideas.
Regardless of what you might think of the casting, I think it's pretty cool that we may get a female-led franchise, and one based around the cool, rational science of forensic pathology. It's the closest thing to a Bones movie that I'll ever get, so I'm all for it.