I wouldn't say he's a villain per say, I'm thinking he's going to be the "Alister Krei" of the sequel with his sister Evelyn (if you combined the name together, it means "Evil Endeavors") is the big bad, tech users are always the villains (if anything Winston is being set up as a possible big bad, only to take the fall later).
I'm also betting that Voyd will also be evil in the end rather than good (as she is an "Elastigirl" superfan, like Buddy was with Mr. Incredible and we saw how that turned out) and they even stated that the new villain will present a big challenge even tougher than Syndrome was, Voyd would present quite a hefty challenge for the Parr family.
Is is me, or does Sarah Vowell's face make me think of this face a bit?: (and since the Doctor is currently played by a female now, I wonder how Sarah Vowell would portray her? (a little off-topic fun if that's alright, now I want to see Violet Parr in the TARDiS.)