Seriously can't see what a 4th film could be about. Trapped on the island, again? Dinosaurs coming to the modern world, wreaking havoc, again?
The original JP4 plot was that the US government created human / dog / dino hybrids so they can be trained to kill the dinosaurs that have made it to the mainland. Thankfully someone released the script and it was ripped apart by everyone on the internet and never made.
So I have high hope that it's better than that.

The dinosaurs are not all CG, they are robots.
True, but with advances in technology it's likely the dinosaurs in the new movie WILL be all-CGI. Or at least to a much greater degree.
And I've seen more than enough giant CG creatures by now that it's hard to get too excited about it anymore, sadly.
I read an article from I think November saying the plan was still to use mostly robots.