I actually tried Linux nearly a decade ago (it was when Ubuntu first became really popular.) I mostly stopped using it because I got tired of rebooting to play games; I actually liked a lot of the aspects of how the OS worked to be better and easier than Windows. I never had to delve into the command line, and there has been a decade of development since then. I'm actually looking forward to setting my system up to dual boot this Steam OS, and may even get a Steam Machine depending on what specs and the price of buying one vs. upgrading my current system (which is showing its age.)
In particular, I found installing and using programs to be much easier than they were in Windows at the time; most programs save the most obscure were installed using a catalog that actually works a lot like Steam (but free because Linux has a ton of open source stuff.) You find the program you want, you click, it installs and is automatically updated.
I really think that if SteamOS works the way it sounds like it should, it will be a best of both worlds thing. Consoles have advantages-- mainly, you plug them in and they work. If these systems function in the same manner, it would honestly be awesome.
I have a blog! Warcraft and other gamer musings. http://oilstainedlibram.wordpress.com/