He will be replaced with a left-wing judge, as he should. I’d like to indicate that filibustering him is really a waste of time because replacing one left-winger with another will not fundamentally alter the ideological balance of the court.
And who will replace him? I maintain my view that it is not going to be Elena Kagan because her appointment as Solicitor General is to groom her for a SCOTUS nomination later. Sonia Sotomayor and Diane Wood are frequently mentioned names. Sonia Sotomayor is a bit more towards the center of the political spectrum, but she is still the most likely nominee.