It's going to be noais for sure.

Valve announced today that Steam will expand beyond games and begin to sell regular software as well. Steam is already a massive distributer of digital games, and by far one of the easiest and most convenient ways to buy and play games. Updating is often done in the background and reasonably painless, your games can generally be played wherever you are and there are several ways to make purchases, even while not at your computer. While you may only think of Steam as a gaming platform, it seems there is a significant enough demand out there for them to release software other than games, and the things that make Steam popular for games would be equally likely to make it popular for regular software.
Starting on the 5th of September, Steam will begin to sell software titles which "range from creativity to productivity," and many of these launch titles will make good use of some of the popular Steamworks features, such as automatic updating, easy installation and, of course, Steam Cloud storage for your files. Following the launch on the 5th of September, developers will be welcome to submit software titles via Steam Greenlight, and as such there will be a constant stream of new software titles coming to Steam from that day onwards.
The 40 million gamers frequenting Steam are interested in more than playing games. They have told us they would like to have more of their software on Steam, so this expansion is in response to those customer requests.
~Mark Richardson, Valve