Amazon.com has the upcoming WoW expansion Wrath of the Lich King available for pre-order. The date this thing is due to arrive is on November 3, 2008. Details are here: Wrath of the Lich King Pre-order
I fully expect that the iDemise guys will have a level 70-80 leveling guide update very soon after the expansio goes live, especially if they're in the beta. Since it'll be a free update you're covered if you grab your copy now. Here's the iDemise review.