Hmm.. What if to have some "quests" for gathering the nessessary war-material for the move 'move'? Like building up food supplies by raiding Alliance camp X (Which could be "defended" by an alliance guild) if we win, we gain supplies, if we lose, we have to tend to the wounded, and plan an other attack and so forth, hope you get the idea, it's just rough.
Ps, say "We" due to the fact that it's easier and more understandable, currently I am not in WoW, though gaining my new gamecard today. Will come back, and applicate again if that is what I need to do, due to the fact that WAR ain't my game, neither was AoC.. Ds.