User blog comment:Swimswimfruit/Dear God.....dont let Eiichiro Goda die..../@comment-80.217.68.75-20110804173415

" Zoro and Sanji know of Haki,since Sanji named haoshoku haki,and Zoro seemed to agree."

Don't forget Robin, she know of Haki too, although it would appear that she saw it (well, saw is not really the right word but you know what I mean) for the first time in this chapter.