The Humble Bundle team and Mojang (Notch’s company. Minecraft guy) are teaming up to create a game in 60 hours. It starts this Friday, February 17th at 10 CET and you can donate to the 60 hour project and all proceeds will be going to charity, plus you get a copy of the game. If they hit certain donation milestones, there will be some fun incentives. If they hit $1,000,000 Notch will shave his beard.
No idea, whether or not this game will end up on Steam. Minecraft isn’t on Steam but all of the Humble Bundles have been on Steam.
If you go to the original blog post, you can vote for the theme and genre of the game. I voted for WWII Dungeon Crawler. Right now it looks like Steampunk RTS is in the lead though. Steampunk Dungeon Crawler would be pretty awesome also.