There has been some reported cases (myself included) of stuck on character loading or area transfer. What they had in common that are EP chars getting into Coldharbour.
Some of them got resolved just by killing the client and retrying, others, like me, haven't been able to log on to that character since today's patch.
You're on an EP char too?
Here's a list of other threads with similar cases:
Haven't been a lot of reports of the problem... yet.