On a side note: Valve will start its new Greenlight project soon.
Seems like they are still afraid to mention Linux
What systems must my game run on?
To remain in Steam Greenlight and qualify for distribution via Steam, your game must at least run on a Windows PC.
You can be also developing for any other platform you like, but we are only able to support PC & Mac releases at this time.
I'm not sure what people wanted.