I think the key to making world bosses work is to fill their loot tables with stuff that, while nice to have, isn't unique. Guilds would still race each other for the challenge, but would not have to resort to camping or griefing to get the upgrades they need to raid.

Something like the VoA bosses would be perfect, they would have a chance to drop loads of good stuff, but it wouldn't be the only place to get those items.

Personally, I think world bosses could really benefit from a contribution system like in WAR. Have it spawn near places where there is a horde town and an alli town nearby to encourage clashing factions and make the boss tough enough that you'll need several people to down it but not so tough that 2 enemy faction players can wipe you.

Then when the boss goes down, everyone on the faction that did the most damage who participated at all in killing the boss or the surrounding enemy faction players (or healing allies in the area) gets a chance at a loot bag (with something class/spec specific for you) based on how much you contributed to the success of your faction.

It takes away loot drama and the old problem of guilds racing to tag the boss before anyone else can. Just be there when the boss is up, jump into the action, and reap the benefits. To make sure everyone gets a chance at the boss make it spawn every 9 hours or so rather than once a week or whatever. Just a thought =)

^^ This... Proudmore sports an Alliance-Horde ratio of 11:1.