Realms have been down today since 3:00 a.m. PDT / 6:00 a.m. EDT. A few realms were up for a short time earlier this afternoon after the maintenance was extended, however they were promptly brought back down.
There is no indication as to what problems Blizzard has encountered. While the official forums and account management are often offline right now, WoW Insider has a few sources where we are getting our information from and we'll keep you updated with the very latest.
Be glad that at least the in-game mail hasn't gone missing, and did you get that pony Ghostcrawler promised you?
Don't forget to check out WoW Insider's Guide to Patch 3.1 for all our patch information, and stay tuned throughout the evening for updates!
Update 9:30 p.m. EDT: Current announcements indicate that most realms are up and available for play, and those that are not will be available by 10:00 p.m. EDT / 7:00 p.m. PDT. Enjoy the evening!
Older updates will appear after the break.
Update 7:15 p.m. EDT: Apparently some folks were able to get in, and some were not. Bornakk has also just announced that despite several servers being active, all realms will be online and available for play at 5:00 p.m. PDT / 8:00 p.m. EDT.
Update 7:33 p.m. EDT: The previous message that realms would be up by 5:00 p.m. PDT / 8:00 p.m. EDT has been replaced by a message saying there'll be another status update at that time. We'll keep you posted...
Update 7:55 p.m. EDT: A few realms appear to be up, but as you can see from this picture, good luck. Most are now locked and down again, however.
Update 8:50 p.m. EDT: A select few realms are up and available for play now. My main realm is active and I've been able to purchase my dual spec. However many other realms are still down. We're awaiting updates.
Update 8:00 p.m. EDT: A new message states that Blizzard has ran into problems as they were getting the realms up, and that they have no definite time frame for when they'll be up again. They will provide another update at 6:00 p.m. PDT / 9:00 p.m. EDT. However, they do state they hope to have realms up around 10 p.m. / 11 p.m.