Shane Black wrote the original 'Predator' script and is also set to direct another for a March 2018 release. No cast just yet, but Arnold might very well be returning. In an interview with The Arnold Fans, Schwarzenegger had this to say:

“I haven’t talked with him (Shane Black) yet but I’m going to meet with him for lunch sometime soon. Just as soon as I’m finished with this (Arnold’s Sports Festival) and “The Apprentice” and all this stuff. But I will get together with him. If there is any news, we’ll of course let you know right away.”

This sounds exciting!