I had a player just email me tonight about gaming tomorrow! This is after we played Thursday and Friday of this past week. He's already got two other players lined up and sounds excited to go back into the Maw. Ha ha. I guess he enjoyed it.
This is the advantage of having a megadungeon; I already have plenty prepared for them to explore-- no worrying about overland travel and whatnot. It also helps that my swords & sorcery city Nidus is abstracted, so I can give them a sense of a huge teeming den of humanity without having to map anything.
It's interesting that my shifting player base adds a sense of verisimilitude to the megadungeon. The party going in today will be different than those of the last two sessions, so there is a sense of events taking place, rumored, that not everyone has experienced in person.