That's Dolph Ziggler (Seriously...that's his in-ring name...) and he's probably the best best guy in the business at making moves look real/dangerous.
No different than any Hollywood Stuntman. Everything is staged and everything is preplanned. That doesn't mean it isn't dangerous or risky.
Obviously that guy knew he was getting thrown. You could see him go with the flow rather than try to fight it. He pretty much threw himself into those chairs. But that doesn't mean it didn't hurt.
All this Professional Wrestling Stuff is just like Hollywood stunt acting. Which is fine and it totally stands on it's own. I just have no fricken clue why it's even mentioned in the same breath as real MMA. There needs to be a much larger seperation between the two, and unfortunately guys like Chael Sonnen come along and continue to perpetuate the myth that MMA fighters are no different than "Pro" Wrestlers.