Coping characters from Vanilla server to TBC question

When Nostalrius releases TBC, how is it going to work with regards to people copying characters/accounts over from the Vanilla server?
What will the process be here? Will you copy just one character? Or can you copy multiple characters? Can you delete a character and copy it again at a later time? Or are you forced to copy your entire account over? Do you retain all your gold and gear and everything from Vanilla when you copy over?
I don't know if the details have been worked out recently or not, but I'm curious about it. I'm leveling up some characters on Vanilla right now with the intent of copying over to TBC when it goes live someday.
What will the process be here? Will you copy just one character? Or can you copy multiple characters? Can you delete a character and copy it again at a later time? Or are you forced to copy your entire account over? Do you retain all your gold and gear and everything from Vanilla when you copy over?
I don't know if the details have been worked out recently or not, but I'm curious about it. I'm leveling up some characters on Vanilla right now with the intent of copying over to TBC when it goes live someday.