Creative world is now up and seems to work fine
NOTE: all items are lost upon leaving the Creative world, so I suggest not taking anything with you when travelling there.
How to get there? In survival, overworld, type /mw spawn, and you will be taken to the world spawn. There you will see a small lighted platform with pressure plates. Upon stepping on them, you are teleported into a lobby, where more worlds will be soon (Minigames are under construction). Follow the signs to a 'Creative' labeled sign, step on yet another pressure plate, and you are in the creative world Just walk in any direction to get Creative and return to the spawn to be teleported back to the lobby (this is where the inventory is cleared). If there were any issues, let me know.
Enjoy!