Because of the blowback from Iron Man 3, lots of people and fans were very upset with the producers and directors of the film for not doing the character properly from the comics over their selfish opinion about his looks. But wait, sure they messed up the Mandarin but it may not be what it really seems. Think about it, if Kevin Feige and his staff knew if a twist on a major character most people knew very well from the comics like the Mandarin would upset a lot of fans which would lead to bigger problems, they certainly would not be so selfishly stupid enough to make that happen without having other things planned and whatever Shane Black said about Aldrich Killian being the Mandarin of the Marvel Cinematic Universe could just be a lie to keep us from knowing what the rest of Marvel Studios has in mind for the main event of Phase 2 and even if Aldrich said to Tony at the end of Iron Man 3;
"No more false faces. You said you wanted the Mandarin... well you're looking right at him. It was always me Tony, right from the start. I am the Mandarin."
He only said that because he was angry at Tony for trying to outsmart and blow him up at the same time with the Mark 42 armor which didn't work because of the Extremis virus inside of him made his body a lot denser than Savin and the other thugs in his organization. And didn't anyone watch the part where Trevor Slattery (the expected Mandarin of the film) was still alive and being brought into custody after Killian had him set up on taking the fall for the explosions? And did anyone recall the rumors of Kingsley showing up for the Avengers sequel in India? Sometimes rumors that may seem false can often be true sometimes and if it is true, then it would actually state that Kevin Feige, Shane Black and the rest of the people involved on making the film may have used the twist and Aldrich Killian as a diversion not to waste the Mandarin but to save the actual character for one of the bigger and upcoming films. As epic as the Mandarin is with those power rings of his, he is most likely to reemerge with those rings in Avengers 2 along with the Masters of Evil. For evidence on Trevor Slattery's return as the Mandarin from the comics in Avengers 2 the evidence for that is right here in the picture below
In the picture shown above are Loki's Scepter,the Mandarin's Rings, and the Infinity Gauntlet and the one thing these items all have in common; they are cosmic. If Loki appeared in The Avengers film and used the scepter given to him by Thanos and was mentioned to be powered by the tesseract and with Thanos being known for using the Infinity Gauntlet and being saved for Avengers 3 then it means that the villain Joss Whedon is using for Avengers 2 has to be another villain that uses cosmic powered weapons and there is only one other popular villain known for using cosmic powered items and that is indeed Iron Man's arch enemy the Mandarin and I have more proof on how the villain from the comics will be the lead villain in the Avengers sequel right in these next pictures below
As you can see from the Avengers movie, Loki used the scepter to brainwash Hawkeye and numerous SHIELD agents into following his commands. Even though the blue crystal that is used to emit energy from the scepter was speculated to be the Mind Crystal for the Infinity Gauntlet and wasn't much similar to how Mandarin uses the ring of influence on his left ring finger it would still show a bit of similarity on mind control but this next picture below should show the more stronger speculation on the character's chance of appearing in Avengers 2
As you noticed from Captain America: The First Avenger, the Red Skull used the tesseract's energy to disintegrate his enemies including those who disagree with his plans and mercilessly those who fail him was very much like the disintegration beams the Mandarin fires from the ring he wears on his right ring finger
And if that doesn't seem to be enough to prove that Mandarin will return as Trevor Slattery then why is the character that Marvel Studios had us expecting from Iron Man 3 is atill alive and why do you think Joss Whedon is keeping the Avengers sequel's villain a secret? Probably because of the variety of powers and abilities the Maandarin's rings possess make him a supervillain so epic that he would fit in a much bigger film in the Marvel Cinematic Universe and so what if he got them from the Makulonians? The producers have a right to alter the character's origin a bit and do you remember what Batman was thinking about in Batman Arkham City before battling Clayface?
The Joker saying: "So how do you keep a secret from the World's Greatest Detective? Well, do you know? It's easy. You stick it right in front of him, right under his long, pointy nose and wait."
And do you happen to recall some of the cast rumors from other movies like Transformers 4 being denied but then actually confirmed? Then this twist from Iron Man 3 is a smokescreen to keep us from suspecting that Mandarin is the villain for Avengers 2 and that Ben Kingsley will be reprising his role. So I would suggest not to take twist or Shane Black's interpretation so seriously and watch some of the past Iron Man shows as well as Captain America TFA and the Avengers and then I'm sure you will see where I am getting at.