If I'm right (I only briefly checked the newest topics), it hasn't been mentioned yet:o) Since it's clear from the title alone, I will just congratulate David for successfully defending his PhD thesis and becoming _Dr._ David Marjanović!:o)
Yes, it's true; I defended on Nov. 19th and officially got the title yesterday. I didn't mention this precisely in order to avoid a congratulations thread. :-) Thanks anyway, everyone.