Yeah Luffy owes that to Zoro, even if he doesn't know about it. Luffy taking a slash or blast that would finish off Zoro would be nice. I don't expect the Strawhats to have an Enies Lobby or Thriller Bark struggle until the arc after this one.
I was actually talking about Sanji doing a self-sacrifice. It'd be interesting if Zoro tried to do another self sacrifice, with Sanji knocking him down all like "NOPE" and taking it instead.