Originally, before the mid-season finale, I was thinking Eddie was the Reverse Flash, but then we saw Wells with the suit at the end of the episode and that pointed to him actually being the Reverse Flash. But what needs to be noted is that while yes he does have the suit, we never actually see him WEAR it.
BUT! There's one more theory...
While yes Wells does have the yellow suit and is hinted at having the super-speed, there is still the theory that Wells is actually a future version of Barry who, after failing to stop some "Crisis" in the future, travels back in time to push his past self so that he can change the future and stop whatever it is that Future Barry (Wells) couldn't. This would explain why Wells is so obsessed with pushing Barry to his utmost limits, even willing to kill and allow others to die. With Wells being a future version of Barry this would also explain how he has powers.
So yeah, my theory is that Wells is actually a future version of Barry who failed to stop some major crisis in the future, which drives him to travel in time to change said future by pushing his past self. This ultimately leads to Wells creating the Reverse Flash, who is Eddie, to push Barry even further and to kill Barry's mother as that is the driving force behind Barry's desire to be a hero.
Though, with that said, I'm still not sure how the Reverse Flash was we saw in "The Man in the Yellow Suit." We literally see Reverse Flash beat up Wells, yet we also see Reverse Flash randomly spare Eddie's life. It could be that the Reverse Flash we saw was a future version of either Wells or Eddie, who is trying to make sure that the past remains the same so that Barry can ultimately face this future "Crisis."