I think this pretty much proves that WoW is on its way out. Why else would a guild want to transfer servers unless the server they are on is dying? Now that Blizzard is offering a guild transfer option, this just proves the fact that Blizzard recognizes the fact that the servers are dying. My wife and I quit WoW roughly 3 months ago after a 4 year run. The new expansion and patches caused too many changes, too many problems and even leveling 80-85 was too linear. Hell even my wife said she'd only go back to WoW if they offered a Burning Crusade server if that tells you anything, and I agree with her. Wrath was too easy but somewhat enjoyable, but Cataclysm just fails.
Let me know when WoW becomes free to play and I might jump on a couple of times a month just for nostalgia purposes.