Just so you know I have two fears...one of which can be seen as being completely irrational simply because its not possible. But these movies make me think it can happen. I'm afraid of heights and Dinosaurs.
But yes Jurassic Park 4's script is now finished and the making of it starts in December. Apparently they got the little boy from the first one Joe to play in part 4. Yup the little boy Tim is going back :D.
Not to sure on weather anyone else is going to pop up at all...but I'm sure.