World of Warcraft is no doubt a popular game. When Ahn'Qiraj was opened there was a "massive" event in Southern Silithus around the actual opening of the AQ Gates. Amongst some of the problems this caused was the fact that the servers got overloaed due to the insane amount of players gathered in one place in one zone. Servers crashing left and right was not unheard of, and queues to get online on the "first" server to open the AQ gates was a perpetual fact. Players have been concerned about this kind of problem repeating itself. This time around, however, Blizzard has decided to take a different yet probably still as entertaining approach to the re-opening of the Dark Portal.
Tseric, one of the official Blizzard posters on the World of Warcraft forums shared his throught with us: it is nice of players to think about these things but there is no need to be worried. He explained in length:
The re-opening of the dark portal is an event that will change Azeroth as we currently know it, and it's only fitting that the tremble of such an event is felt throughout the world. It's still likely that players will group up at the portal, but the event we're planning won't encourage it as the AQ event did.
Hopefully he is right, and the servers will remain stable. One thing is certain though, it is probably smart to have a good book or some similiar form of entertainment handy should the server in fact go down!