Well, it appears the next Munchkin will have a Pirate theme, Munchkin Booty.
I really wonder how long Steve Jackson can push the game system. Now, I'm not SJG basher. First off, I like the Munchkin games. I like the game system. I like it's silliness. And I don't think there's anything worng with SJG milking it for as much as they can. You get a cash cow, milk it. Lord knows there's plenty of flops and follies in the gaming industry.
Still, at some point I would think that the games will run out of steam
So far we have:
Munchkin (+5 expansions) Dungeon crawling
Star Munchkin (+expansion) Sci Fi movies and RPG
Munchkin Bites (+expansion) Vampires movies and RPGs
Munchkin Fu (+expansion) Martial Arts movies
Super Munchkin (+expansion) Super hero comics and movies
Munchkin Cthulhu (+expansion) Lovecraft mythos
Munchkin Impossible James Bond-style spy movies
The Good, the Bad and the Munchkin Wild West mobes and TV
So, how far can they go?
Some available themes include Indiana Jones-style adventuring, World War II movies/wargaming and Detective/police procedurals off the top of my head, which would be enough to get to an even dozen.