Obviously the theory of Wally West being the new Reverse-Flash has been speculated by many, but most seem to presuppose this would introduce the New 52 version of Wally West into the current continuity. What if instead, the new Reverse-Flash is none other than the pre-New 52 Wally West, whose marriage and offspring have been erased by Barry Allan's actions in Flashpoint, and who as a result is seeking to undo the damage to the time-stream done by Barry and Pandora. This in turn could lead to a Zero Hour type event called Flashback or Shatterpoint, where Wally in fact does succeed in undoing a small portion of the changes made by Flashpoint (this would essentially have been DC's way of seeing what has worked* and what hasn't** after a two-year long experiment, and then combining the best of both the pre-New 52 and the New 52 into a single, definitive continuity).
*Such as Court of Owls, Death of the Family, the Trench, the Others, Throne of Atlantis, Green Lantern, Animal Man, Swamp Thing, Shazam, Starfire's new personality, etc.
**Such as "Red" Robin and the five years of "internships," Alan Scott of Earth-2, Superman's Kryptonian Armor (the single worst thing to happen to the comic book industry since a man by the name of Fredric Wertham published a book called "Seduction of the Innocent"), etc.