First of all, we still don't *know* that Killian is the big bad. It's still just a rumor.
Anyway, Feige and Black's comments about Mandarin don't do anything but justify his change in image. He went from the racist Fu Manchu to a more believable modern day villain. It's wrong to assume that making him the lead villain means recycling Middle Eastern terrorist cliches. First of all, we don't know where he's supposed to be from. He could be from Mongolia for all we know. Second, having your non-Western villain outsmarted by whitey and his tech gadgets has already been done in IM1. Do they really need to repeat that scenario? I hope they don't. It's lazy.
My biggest problem with the whole rumored bait and switch is that it absolutely destroys Iron Man's greatest nemesis. I don't care if he's a badass for MOST of the movie. This is his introduction, much like CA:TFA was Red Skull's and Thor was Loki's. If he's outsmarted, manipulated, or otherwise controlled by a villain like Killian, it kills any future threat level. He's no longer nemesis status and goes straight down to B-level hood. THAT'S my main worry. People would scream bloody murder if Joker or Lex or Loki got used in such a way their first time out. Mandarin is Iron Man's most well-known villain. Treat him that way.
