During an interview with Collider, The Flash's Rick Cosnett declined to speculate whether his character might evolve into the Reverse Flash...but he did characterize Eddie as Barry Allen's "opposite."
Of course, that makes some sense on its face: Eddie is a hero cop with a lantern jaw in real life and a secret past, while Barry seems a bit inept as Barry but as The Flash is a hyper-competent hero with a secret present.
Nevertheless, it's hard to overlook a quote like "I think there’s going to be a wonderful tension between the two, and they’re so juxtaposed. They’re pretty much the opposite of each other," when it's coming from the guy widely speculated to be literally the hero's opposite.
He also indicated that his character undergoes a lot of change prior to the midseason finale, currently being filmed, in which on-set spies have snapped photos of the Reverse Flash.
"At this stage, you don’t want to look too far ahead, as an actor," Cosnett said when pressed on the issue of the Reverse Flash. "Obviously, you want to know where you’re going, but you want to be constantly surprising yourself, as you go through the journey, so that any information that comes at you is new, as it is in life. So, I don’t like to read too far ahead. I just want to go on the journey, and let the audience go on the journey with Eddie. But, Eddie has already changed. He’s gone through a big process. He has a big arc, even in the first nine episodes. It’s been crazy! As an actor, you live for this stuff."
The Flash airs Tuesday nights at 8 p.m. ET/PT on The CW.