Serious Sam HD: The Second Encounter comes out sometime in early 2010, Croteam and Devolver Digital announced today. I was going to make a pun, but the title of the game sort of precludes puns.
The First Encounter hit Steam in the last week or so and is due on Xbox Live Arcade very, very soon. The Second Encounter introduces a cooperative tournament mode for teams to compete against one another. The mode is getting some face time a the upcoming 2010 World Expo in Shanghai, China where players can compete for the Digital Youth Award.
Hopefully that means the game will be out before the World Expo so that you've got time to practice.
P.S. Sorry, no screens yet. You'll just have to stare at a screen from The First Encounter instead.