He doesn't have any plans for other games at the moment, and WTCTR is likely his last game before he takes a break or stops altogether. http://middens.tumblr.com/post/85648173870/after-the-next-game-do-you-have-any-plans-to
He hasn't stated that he has any more plans. However, he has stated that he might produce a new work that isn't a game after WTCTR.
I'm inclined to agree with him about Steam. I just do not like the platform what-so-ever. Steam and I have never really been good, in all honesty, mostly because of computer difficulties.
I do sort of share the view that indie games shouldn't attach themselves to any particular platform. In my opinion it takes something away from it, but I'm not entirely sure what that thing is.
Have a poorly-animated Nomad shooting, courtesy of me.