In all seriousness, Patch 3.0.3 has been as good as confirmed for tomorrow. As was pointed out to me, while the breaking news announcement about tomorrow's maintenance doesn't explicitly say it's an extended maintenance, the timeframe for it is definitely longer than the norm. Moreover, Boubouille over at MMO-Champion says it's tomorrow, and that's as close to confirmed as it gets without... you know, a confirmation. When he opens his mouth, blue crayons fall out.
As always, WoW Insider will be here in the morning to help you through the patching process, from the hours of boredom to the stretch of discovering just what the heck is different. And as I mentioned before, if you're a US citizen, you have other things to do as well.