Sometimes when this happens, it means the world server itself is down -- check to make sure that you can load other characters, on other continents. For instance -- can you make a new draenei or blood elf character (hosted on the Outland world server)? Can you load characters parked in Northrend? In an instance? Do you have the same problem on a completely different server?
If you are able to do one or more of the above, it is likely the problem is either location or character specific. In either case, it is likely that time will resolve the problem, as parts of the server are brought back up. If, on the other hand, the problem persists for several days, I would try opening a ticket, or speaking to someone on the customer service forums.