I was in Karazhan and this is probably old, but maybe many players didn't know it, so I would like to point out how we could already have some hints about Northend, Cataclysm and Pandaria by the time we were raiding there.
See how each circle shows each expansion since TBC.
http://i45.tinypic.com/pxmc.jpg
UPDATE: It looks like it could have been patch-updated. However, why would they keep the basic polygonal structure rather than simply change the entire globe? It takes about 5 minutes to open the file and update it, making it look more like a globe and less like a.. square.
This is the room where the globe stands.
http://i45.tinypic.com/2ns2d0l.png
UPDATE 2: A GM couldn't really tell me. Unfortunately I was afk just when he did answer so I can't know his personal opinion.
I'm interested because it could mean that we can find much more about the incoming expansions than we already might know (clues at least, and that's always fun for the lore lovers!).