It would be the hotness if calendar could be shared in a CalDav format so I could sync to a R/O version on my iDevice.
Also, if you import the in game calendar in WoW to the website calendar, can it figure out if people sign up and sign them up here?
Sort of a "Oh look! Frommers signed up for this event in the game. I don't see him signed up here, but I do see a level 85 gnome mage named Frommers in the guild. I'll just sign him up here too!"
I don't know if that would change my signup routing, but it is a neat idea.
--