I think it will be a slow burner. With time, I can see it getting up a head of steam (see what I did there?
I like the idea of dual booting eventually. I use Steam big picture mode now and then. Even though the DS4 controller is supported by most of the types of games I have played on pc to date, it's stil not seemless. BF4 and Fallout 4 being two high profile examples.
If the majority of games start to become optimised for Steam OS, with full (console) controller support, I wouldn't hesitate in dual booting. It's a wait and see thing for me.