According to Marshall, Indy 4 will immediately begin following Ultimatum. He hadn't read the script yet, but noted the project is moving forward and that everyone involved is very happy thus far. He would not confirm whether or not Sean Connery would return as Indy's father. After Indy, Jurassic Park 4 will begin its production. Hmm, so they are going ahead with it. Why?
I'm afraid that's as far as the good news will travel and, depending on your stance, the rest of it may bum you out. Marshall also officially squashed rumors of another Gremlins film and said that a Back to the Future 4 will not be made. Oh well, they could've just saved time and merged the two, having Mcfly travel back to the year 1984 to help fend off Gremlins and save Christmas. Then again, I'm not in charge. Damn.