The official WoW site has this note:

We've recently completed an extensive upgrade on our web infrastructure that will allow us to provide new features in the future, along with increased performance and security for our players. All web-based features and services are once again online and available for use. We apologize for the longer-than-anticipated downtime for the website, and we're taking steps to ensure future upgrades are completed in a timelier manner.

Hopefully the problems people have been having lately will all be gone now!