I've been recently been engaged in the Draenor/Mag'har Orc debate and it got me thinking about AU Draenor's place in our timeline and I've thought of a radical/not-so radical idea, that being AU Draenor is actually in our timeline.
But first it's best to explain what we know about time travel in the warcraft universe. We know from Aman'Thul that there is one true timeline (Ours) and therefore presumably nearly infinite insignificant alternate ones, and that there will be some people who wish to change ours by going into the past, which our own characters have done several times. This has always been at the behest of the Bronze Dragons and therefore no change to the Main timeline have occurred.
We also know that there are many alternate timelines, some diverging only moderately from our own (AU Draenor) and some vastly different, Thrall-dying as a baby timeline, Hour of Twilight, etc. Kairoz's time shard thing has shown the ability to bring characters from these timelines to our own (War Crimes Novel) and have them interact with their MU counterparts without destroying our timeline, presumably because they are not from our past. So what if Kairoz physically brought the whole of AU Draenor into our universe, presumably taking up MU Draenors (Outlands) orbit around it's star. Outland can be assumed to be partially or at this point entirely submerged into the Twisting Nether akin to what happend to Argus. Vargoth states that Outlands situation is deteriorating constantly, the correlation could be that the more Outland enters the Twisting Nether, the more it degrades.
While this theory does sound tin-foily, I believe this may have been blizzards original intention. I distinctly remember a blizz employee being asked about this at Wods blizzcon (maybe even Metzen himself) and responding that it's like if someone went in time and brought and chair/table (I forget the example) and brought it back to out own. This could have been an off the cuff remark and i can't find the question and answer. This theory would also explain why the Burning Legion we fight in Wods is our own.