Well, the novel is definitely coming out, so too bad.
There are a lot of deceased authors who are still "producing work", BTW, (Ian Flemming, J.R.R. Tolkien, H.P. Lovecraft), or still-living authors whose name has become a brand ALA Tom Clancy, and a lot of this new stuff is pretty good; I'm not sure if Kathleen Kennedy's argument of "he's dead, so there will never be any more Crichton stuff" makes sense, really...?
Lincoln Child and Douglas Preston are basically "Crichton-lite", so they're definitely candidates. Others would be Steve Alten, David Goleman, James Rollins or Scott Sigler.
Panther, Crichton's agent stated that they're not planning to have someone else writing under his name, but inferred there may be partially-completed novels, or notes for novels, in Crichton's archives which could be fleshed-out and published in the future.
I'm hoping he started a third novel in the JP universe which may be finished one day...well, I can dream.