DNS entries for blizzard.com and worldofwarcraft.com point to cerf.net, while the DNS servers for wowarmory.com are currently pointing to domaincontrol.com. While some of you might be seeing wowarmory.com work correctly, others are not. The ISPs of people who are seeing it work have not had their DNS records updated yet, however within the next 48 hours they will see wowarmoy.com go down as well; unless Blizzard fixes this before then (I am sure they are already aware, or becoming aware of it).
Stay tuned to WoW Insider for the latest on this story.
Thanks to Matthew Rossi and his wife for contributing to the technical sleuthing in this post.
Updated 2:34 p.m. EST: You can access the armory using a sub-domain of worldofwarcraft.com by going to http://armory.worldofwarcraft.com/
Updated 3:03 p.m. EST: http://www.wowarmory.com/ is now working again. It looks like Blizzard really jumped on the issue and fixed it.