There is definitely a ton of potential in Linux and I'm sure with Valve backing it strongly now, there will be even further developments. "Free" is a very strong motivator. The thing is, I don't see Linux going mainstream for a very long time. The only way it can possibly compete is to be an option for pre-built computers. While we do see Linux in stores in some products, the ratio is almost completely one-sided. We've seen what happened with 8 and because of a lack of a tutorial, many were confused. With Linux, it would definitely be worse in that aspect.