Hey, It's That Guy!: Arnold Schwarzenegger and Jesse Ventura were both elected and served as state governors; Sonny Landham also ran for governor but lost.
You might not recognize Hawkins, but he is the guy who wrote Lethal Weapon. In fact the studio requested that he be in it in order to have an experienced action writer / producer on the ground to make sure director knew what he was doing.
Private Hudson had joined the LAPD. This time he takes the situation with a cool head. Given the canon connection between the two series now, perhaps he's an ancestor.
What Could Have Been: Keyes was originally going to be Dutch (once again played by Arnold Schwarzenegger), and Anna was originally going to appear again. Her face is seen on the screen while Keyes show Harrigan videos of the jungle from which the first film took place.