If you were attempting to play this evening, you may notice your realm vanishing out from under you. That's because Blizzard has been in the process of rolling restarts to fix a serious issue with today's 2.1.0 patch. As of 3:45 PM PST (that's 6:45 PM to you east coasters), restarts began, with an anticipated downtime of 15 minutes for each realm. The problem that caused all this hubbub? The official forums are a bit flakey this evening, but reader SirCasey reports that stacked items taken from mailboxes are vanishing from players inventories -- and I don't know about you, but I can see this resulting in hundreds of gold lost. What to do if you've already lost something? Blizzard poster Hortus says talk to a GM, but makes no promises that they'll be able to restore items.
Update: CM Drysc reports at 6:30 PM PDT (9:30 PM EST) that complications from the earlier fix has prevented some realms from coming back online. However, they're working on bringing the remaining realms back online and plan to have all realms back online by 9:00 PM PDT (12:00 AM EST).