According to Horror-Movies.ca on Jan. 27, 2013, it reported that William Wisher had in mind a plot for the "Terminator 5" and Terminator 6" movies. Wisher had written a 24-page movie treatment depicting plot of "Terminator 5" which corresponded with both story lines of "Terminator 3 Rise of the Machines" and "Terminator: Salvation".
Wisher, who had worked with James Cameron, had also co-wrote for the original movie and second movie as well. He did express interest in writing for "Terminator 5".
Wisher did back out of "Terminator 3" and "Terminator Salvation" out of respect for Cameron, but if given the opportunity to write for the new movies, he'd bring back the introduction of Skynet, Sarah Conner, John Conner, and Kyle Reese. Of course Conner was considered dead, but she only had a coffin full of weapons, so it begs the question where her body may really be located.
It seems that Wisher wants to continue where John Conner left off when he entered the Bunker with Kate Brewster, played by Claire Danes, and wanted to produce a story that evolves from when Connor answers distress calls from military bases all over the U.S. The ability for Connor to connect with others and giving rise to the rebellion against the machines would give great interest.
Also, there would be new terminator generated technology that would include "bouncing betty" related terminator machines that pop out of the ground and unleash a fury of ammo at its victims. Another terminator-type would be something similar to the liquid metal of the T-1000, but this time they can combine together to form a larger version of itself. Not unlike the Constructicons of the Transformers.