User blog comment:Yonkou Rome/Zoro's Haki/@comment-1691106-20101015060233

Zoro is one of the future pirate king's right hand men, of course he'll learn haki sometime down the road, whatever that haki type is. He's obviously capable of using it at this point, but whether he has the knowledge already or not will be something we find out later.

Cutting Mr. 1 had nothing to do with haki, he simply figured out how to cut through steel, something he's done quite a bit since.