There can be no recess appointment.
O'Connor's retirement does not become effective until her successor is confirmed.
There is no immediate vacancy to fill.
You are so right. I seemed to have forgotten that Day O is sticking around until the new #9 is confirmed.
In my zeal, I forgot good common sense. :)
It is an interesting question. How is a nomination justified if there is no vacancy? What would happen if the President's will (recess appointment) butted heads with Judicial prerogative (timing of own retirement)? Would O'Connor step aside if a replacement was named through Constitutional means?
The plain language of Article II does seem to clearly express the conclusion that you reach ...
Article II
Section. 2.
Clause 3: The President shall have Power to fill up all Vacancies that may happen during the Recess of the Senate, by granting Commissions which shall expire at the End of their next Session.