Here, he mentions Jurassic Park 4:
So, Jurassic Park 4… There are rumblings and rumours. Have you been contacted, and would you be interested?
I know they are writing it and it’s been developed right now. The last time I saw Steven was at the Emmys and I put the bug in his ear, I have no shame in that! I said, ‘Hey, let me know when you’re doing Jurassic Park 4, ok?’ If it came around and I was a part of it that would be an absolute thrill. I think it would be a great idea to have Tim grown up and see how that would affect things. We’ll see, you never know. If it happens it’ll be the greatest thrill of my life.It would be AMAZING to see Joe back as adult Tim in the fourth movie. Steven Spielberg has mentioned that a script is in the process of being written and the movie will be out in a couple years or so.