Let's indulge in a little thought experiment. Let's say that your favorite MMO has enabled the salvage of an entirely unique, singularly powerful weapon/item. And by 'unique', I don't mean 'Legendary', I mean 'only one person per server may have this thing'. It binds on pick-up for 24 hours, then disappears from your inventory, to become available for the next person to find it.
Let's say that for those 24 hours, the wielder of this object is untouchable. Would such an item help or hurt your favorite MMO? Sure, it's an unbalancer, but it's also a goad. If it can only be found, then everyone gets an equal chance for it, no favorites. And who wouldn't want to be GM (or the combat equivalent) for a day? Of course, we know what passions uber items can arouse in the hardcore, but what do you think? Good or bad idea?