As others have said, the important point here is that the core of Linux support is here. They've already ported all of their major titles to Ubuntu-based deskto

As others have said, the important point here is that the core of Linux support is here. They've already ported all of their major titles to Ubuntu-based desktop linux, and I would be extremely surprised if SteamOS did not inherit greatly from that effort. Even if SteamOS uses different toolkits or packaging (which it very well might), the amount of effort to get those titles to run on typical desktop linux distros should be relatively very minimal. I highly doubt it would be more similar to Android than Linux Mint simply because they have already invested time and money into making Steam run on the Linux Mint family of distros (i.e Ubuntu), and (to my knowledge) none working on the android stack.