I actually think this is a really fun question to think about. Especially if you assume he gets his US citizenship.
He will have a very tough time making a world or olympic team in the 5k. He's obviously talented and is dominating the college ranks, but the pros are at an entirely different level than both him and his competition.
Paul Chelimo!, True, Kipchirchir, Jenkins, Mead, Hill, Jager, Chelanga, Korir...heck, I think that Lagat would still be in the mix if he chose to unretire from the track (heck, he was 5th in the olympics!). Where does Ches fall among that group? I would not put him top 3
What about the 10k? or the mile? I suppose that at the moment, he doesn't seem to be focused on a single event because of team points. That being said, I think Ches has a ways to go before any of the pros look at him as the guy to beat.