Isn't that similar to what a datacentre is, a 'mega server'? What they need to do is balance the existing servers across the datacentres to achieve an even population distribution & also implement datacentre wide party finders for instanced content. It obviously wouldn't work for Hunts or in world content but since when has quiet hunts been an issue?

A mega server where everyone shared world content, & where you could get possibly a few thousand people idling in Idleshire with minions out, is a rather horrifying concept to many of us. The use of AoE spam & ridiculous shouts would deter many, I feel.