On October 15th, Valve will announce at least 10 of the next games that the community has voted up and will move them to the 'Greenlit' section of Steam Greenlight
Steam Greenlight is a system that enlists the community's help in picking some of the next games to be released on Steam. Developers post information, screenshots, and videos for their game and seek a critical mass of community support in order to get selected for distribution. Steam Greenlight also helps developers get feedback from potential customers and start creating an active community around their game as early in the development process as they like.
Check out the Steam Greenlight blog
for more details on today's announcement and recent updates.