On the StackOverflow podcast, I believe he mentioned something about not wanting to dominate the blogging world anymore. Someone says "Joel" and everyone else thinks "Spolsky." Yet, he doesn't mention that at all here. I wonder what's up with that?
Also, he says he's going to quit "for the most part" podcasting and public speaking. Is this also the end of the StackOverflow podcast? Seems unlikely that he'd force that onto Jeff, who seems to like it a lot.