Are we sure that's what it is? That sounds more like a one-shot about Loki ruling Asgard.
It may be, I'm only reiterating what's been reported.
And don't forget, Ben Kingsley did reveal months back he was working on a One Shot which would reveal the real Mandarin paying Trevor a visit. It seemed like that might have been a false report, until now.
Also, it's important to remember the One Shots tend to be disconnected from the films they're released with, least lately. Hence Agent Carter being released with the Iron Man 3 Blu Ray, and this arguably IM3 centric One Shot being released with Thor - The Dark World.
Of course, it could be a Loki centric short occurring after Thor 2, but I doubt it, as I don't see them touching on that major plot line in a 5-10 minute shirt film as opposed to just waiting for Thor 3. However, the whole "real Mandarin" thing I can see being the subject of the One Shot, as it addresses the complaints some people had, without it being necessary viewing, but also opening the potential for that "real" Mandarin thread to be picked up or explored in a possible future IM movie (IM4?) or Avengers film (Avengers 3?).
I'm not saying it is one way or the other, only rehashing what info we've received and trying to make sense of it. We know Ben Kingsley hinted at his involvement in a post-IM3 One Shot that involved his Trevor Slattery character meeting the "real" Mandarin, we've got confirmation a new One Shot is coming, and given the "All Hail the King" title, I'm thinking that pertains to the actual Mandarin, not Loki.
We'll get more news in the coming days/weeks, and find out for sure, but I do think this One Shot is the one Kingsley mentioned months ago, not one we hadn't heard of at all.
There's been no info given about the one-shot so stop trying to shove your religious beliefs on me DIrishB!
There's been info given about an unnamed One Shot starring Ben Kingsley. This is that.
Besides, Cap Canuck is the religious one. I'm just the detail oriented one.