It was always known that Zoro is the right hand and Sanji is the left hand of Luffy. This is great confirmation on Oda's part within the canon storyline. Sanji will probably do something really epic. Oda hears the slander he receives and people may be tight lipped once they realized how important and powerful Sanji is in the end.
Sanji vs Queen will open a lot of people's eyes. His fighting should be coming up soon.
Robin vs Black Maria ends next chapter. Xdrake vs Apoo(less than a chapter), Killer vs Hawkins(1 chapter), and Jack's fight (1 chapte, luffy could actually one shot him) could all settle before we see Sanji vs Queen fully.
so 5-7 chapters before Sanji vs Queen.