Rehnquist is battling cancer and Scalia is already trying to move into the Chief Justice seat before it is even vacated. This man has no tact to be joking about the future of one of his colleagues health. When a colleague is ill, you don't start using his title, even as a joke. A man with class would say, "the issue of who will succeed Chief Justice Rehnquist will be dealt with when and if he steps down. Until then, I, and the rest of the Supreme court give him our prays and complete support in a full recovery."
A slimy man, like Scalia, starts elbowing for the job while his colleague is in chemo.
Scalia Won't Discourage Chief Justice Talk