I received this e-mail update through some back channels. It is from a Tesla high level employee in Ownership Experience dated 11/20/12:
"George asked me to reach out on his behalf to provide further information about the rear facing seats.
Rear facing seats will become available in early January.
Taking into account the backlog, I would estimate delivery for customers will take place in late January early February."
It does not address who will get them 1st, new owners or 'due bill' owners.
Of those 'due bill' owners it does not address what the priority for installation nor the process for the installation (time with the car, etc.) will be.
I choose not to speculate here on that.