The Jurassic Park franchise has been having a rough time of it over the past few years.
Still, the third film was enough of a success that a fourth installment was put into development. The question was where to take the franchise. Various ideas were tried out, including one involving a squad of super-smart Velociraptor trained for special ops missions, but no one could agree on a story. Then, last December, producer Kathleen Kennedy suggested that the franchise might be dropped. Michael Crichton, who wrote two novels the films were based upon, had passed away and it seemed like a good time to retire the series.
There is still some hope that the genetically-engineered dinosaurs might come back, though. A few weeks ago producer Frank Marshall mentioned that Jurassic Park IV is still up for consideration, even if he admitted that it was a "back-burner project." The difficulty is figuring out where the films should go next, especially since the last film was so poorly regarded. The people-fleeing-from-dinosaurs-on-an-island bit has been done. The franchise needs something fresh (and not space dinosaurs), but we will have to wait and see if any writers can deliver.