Looks like it's in the works, with possibly Cruise returning as Maverick. Isn't Tom Skerritt dead? I guys 50 year old Tom can play that character. I don't think Val Kilmer will be doing the shirtless volleyball scene.
http://hollywoodlife.com/2015/06/27/top-gun-2-tom-cruise-returning-maverick-sequel/
http://hollywoodlife.com/2015/06/27/top-gun-2-tom-cruise-returning-maverick-sequel/