I don't know who Reverse Flash/Zoom is, but I'm pretty sure that it isn't Dr. Wells. Why? Because the photos appearing on newsarama of future Flash episodes show RF/Z in costume and its not the actor who portrays Dr. Wells. Completely different build.
Indeed, the photos do seem to shoot down the idea that Wells is Professor Zoom/Reverse Flash.
The idea that he is Metron of the New Gods however is one to keep in mind.
As to who Reverse Flash is, he is a sociopath from the future that is fixed on Barry and has all the same powers as Barry,.