Whatever your most time-consuming WoW task, it's probably not as time-consuming as Doubleagent's recent grind up to level 90 without choosing a faction. But now that it's proven you can reach end-game levels without picking a faction -- and thus being able to leave the Wandering Isle -- will others be jumping on the bandwagon to be a max-level neutral? With 174 days /played to get there, I'm guessing no.
However, there are plenty of players who are willing to dump lots of time into getting achievements like The Insane -- and without much to do until Warlords -- maybe I'm wrong. So whether you're planning to level a neutral of your own or not, why not get talking about long-term WoW goals -- what's the task you've spent the longest on in WoW?