Terminator 1 and 2 were obviously masterpieces. I enjoyed T3 but disliked how it retconned T2. Salvation was very underwhelming compared to the previous 3. I was hoping that Cameron was involved, and it would be exciting like T2 (although based on Avatar, it's questionable whether T5 would have been good even if he was involved), but if we're just going to get some more underwhelming popcorn shlock like Salvation, I may just skip this entirely.
Hell, where can they even go with it? We've followed John Connor's life right up to Judgement Day, so it's not like Skynet can send another terminator back for him. We've seen after the fall, we've seen the events that led up to the first film, and we've seen how Connor's life came full circle. The story is over, unless they are going to focus on humanity winning the war, and IMO, that sounds boring, especially after Salvation. As stated, since we've seen JD, there can't be anymore time-travelling robots. So where to go? You can't add more to something that is complete.