[The Search function was not taken into consideration in the making of this thread. Countless other threads have sprung up before this one, specifically one on MMO-C. (It is filled with speculations and evidence much more substantial than this)]
Alright, first off, lets start off with the main thing here, Alagon in Ulduar stands next to a globe of Azeroth as you all may possibly know.
Azeorth Map:
Alagon Map:
Look at the map. Notice a difference? [Pro-tip: Look at the middle of Kalimdor]
Going by on what "The site that should not be named" and countless speculators have stated. Barrens will be split in two, 1K Needles will flood, etc etc. This map details every one of those events.
This is not a photoshop!! Go do Alagon yourself if you do not believe me.
Now, a little extra for you non-believers..
Back in Vanilla, the map looked like this..
When Burning Crusade came out, and you zoomed out to the point you saw Outland and Azeroth, you could see Northrend (I'm sorry but I have no pics of this one, just log on wow and zoom out of your map (default: [M] on your keyboard)).
A little extra for your pleasure..
When Black Temple was released, not many people caught this, but you could go to the upper part of the temple (Mother and up) and you could see Azeroth staring right at you in the sky.
This Azeroth was different though, this Azeroth had an unknown continent north of the Maelstrom. That unknown continent turned out to be Northrend.
If you don't see where I'm going with this, BC hinted the next expansion being Northrend, now WotLK is hinting the next expansion completely destroying the middle of Kalimdor.
Who knew you could learn so much from such a small detail of such a big instance?
Edit: I'm sorry for image sizing, I sadly am a bit half-minded when it comes to that. I hope it doesn't trouble you too much.