Some players do not mess around, from Wow Insider
Really good news for serious World of Warcraft players. It looks like Blizzard, starting with Wrath of the Lich King will store all your customized UI odds and ends—dungeon maps, coordinates, threat meters, etc.—server-side. That means if you’re away from your main WoW machine, you’ll still have the same interface you’re used to, and not the bare-bones default one the game ships with.
That’s what someone who’s playing the beta right now claims, at least. It could well be that by the time the game goes gold, Blizzard may change its mind. That wouldn’t make any sense, though, as this is a feature that’s been requested for quite some time now.