See, now this idea is somewhat neat. Primarily because it's do-able (well, somewhat) and actually serves a purpose. Some of the systems are already in place with the way CM's are designed. The hard part, and truthfully probably the reason they wouldn't do this, is having all the servers from a region being interconnected to where each Ironforge has the correct guild info to show, etc. Battlegroups are already connected but every server isn't connected.
It brings up a good point, I'd LOVE to see the bandwidth usage between all the servers, and total from all the servers. Would be something to marval at, that's for sure.