Square wants you to know that Final Fantasy XIV's world transfer service is now available. There's an in-depth explanation post now appearing on the Lodestone, but the long and short of it is that if you fork over $18, you're pretty much set.
One thing to note is that while "multiple characters can be transferred from one world to another with a single use of this service, multiple characters from different worlds cannot be transferred to the same world, nor can multiple characters from a single world be transferred to separate worlds."
Got all that? Good. More info is available via the links below.