When to will we get more specific information on Transfers!

[Ayerinn]

I suspect when you log into Mogstation and do the server transfer steps you'll see which world are designated servers. I'm sure that info will be up shortly after launch and when Mogstation is out of maintenance.

Edit: Aww... I was hoping to transfer to Siren. Does one know if it's free to transfer to any server?

It is free to transfer to Omega (the new EU server) from any world. It is free to transfer from Gilgamesh or Balmung only to designated worlds of Coeurl, Zelara, Goblin, or Mateus. There are some incentives to transfer or start a new character on any of the designated worlds, but the free transfers are limited to the aforementioned restrictions.