As some of you have already said, they completely blew that one. Like straight out of left field and out of the park. To be honest, I wasn't too disappointed because the comedy of the entire thing mitigated the disappointment for me...
I really thought this was what was going to happen:
(a) Madarin (Kingsley) is revealed to be a fraud ---> (b) Aldrich (G.Pierce) reveals himself to be the Mandarin, as he does in the end ---> fast forward to after Aldrich has been killed and Kingsley has been arrested...
(c) A new cut is revealed after the credits have rolled (in prime Marvel fashion), showing Kingsley sitting in dark jail. He sitting there calmly, starring off into the darkness of his cell. All of sudden we hear gunshots and explosions. The din of violence, and of innocent men been murdered draws closer. Then silence, suddenly.
[Camera shot of Kingsley face, with eyes apparently closed, showing the entrance of his cell behind him]
Boom!!! Explosion. The heavy metal door that serves as the entrance to the cell falls flat (inside the cell). Camera shows Kingsley with his eyes still closed, seemingly unaware of all that is happening. Through the dust, smoke, and particle debris, a man followed by others (all wearing military type fatigues and carry military style weapons) steps through the gateway. He slowly walks to Kingsley, who still remains unaffected by the recent series of events while maintaining his place on the dirt floor.
The man kneels down, to Kingsley's level.
Kingsley, with eyes still closed, asks in a commanding voice: "Did you find it"?
The man subserviently replies, "Yes!", then pulls out an rustic looking case bounded by hackneyed looking fabric with imperceptible script etched on it.
He gives it to Kingsley, who has finally opened his eyes.
[Camera focused on Kingsley's face, as he looks down on the case--which is not in the frame].
Kingsley opens the case [Camera still focused only on his face], and glimmering shimmers of light emanate from the case. The light dances about his facial features, revealing the contorted smile of a shrewd and depraved man.
Camera shifts back to the kneeling henchman, who too expresses a certain joy; though his is cautionary, and betrays the fear that is really playing out in his heart.
He whispers: "The Mandarin lives..."
Screen goes black.
If that was too dramatic for you, here's the boring and truncated version: after everything, Kingsley is revealed to be the real Mandarin, and everything we witnessed in the movie was a highly orchestrated charade concocted by him with the sole purposes of facilitating his attainment of the mysterious casing that is delivered to him by the henchman. What's in the casing? We could've have found out in IM4 or Avengers 2.
Like that's what I thought would legitimately happen, on some "the greatest trick the devil ever pulled was convincing the world he didn't exist" type steez. This is the Mandarin, after all. Instead they really just made a mockery of the character. A mockery of Iron Man's greatest foe...
I'm tired of Iron Man always having some wack *** ailment. IM1, they took his power source...so he was weak at the end. IM2...an overall disappointing film but he had diabetes or some **** most of the movie. IM3...he's stuck in Tennessee and having anxiety attacks. Like...is this man ever going to be in his suit and a damn beast for an extended period of time? Got damn. 
