Nintendo would never share royalties with Steam.

If they wanted to do this, they could just simply make their own "PC in a box" basically and let third parties easily port their games over with a few lines of code and then collect a licensing fee.

I thought the Android OS was a good idea but Nintendo shot that down.

Except theres at least 100m+ people who don't game on PC or have heavy preference towards consoles. If PC doesn't threaten the success of playstation and Xbox whos success is mostly down to third party titles which are also on PC, it certainly won't have a huge effect on Nintendo

No, most AAA-games won't work on SteamOS.

> impying they don't anyway

I wouldn't discount that so quickly. The last two times Nikkei reported something big about Nintendo, Nintendo denied it both times, and then a few weeks/months later we found out their reporting was basically correct -- Nikkei reported Nintendo was making a 3DS XL, which Nintendo denied the next day, but then formally announced 3 weeks later. Nikkei also reported that Nintendo would make smartphone games, something Nintendo again denied the following day, but then officially announced a few months later. 

Not sure where did you get there - SteamOS/Linux library is laughable compared to full Steam Store and most AAA titles are not there.

Yeah but isn't that because it's still in beta fase? Steam boxes lauch in November. I thought eventually every game sold on Steam will work under SteamOS?

Steam Machines are just PCs with the Steam OS loaded onto it. If Nintendo makes their own OS and keep their games exclusive to their OS then they would have no worries about royalties to Steam. Its part of the open nature of PC. I think it would be a different story if they are including the Steam Store, but otherwise it could happen.

Oh I didn't know steamOS doesn't have the same support as the steam store. That changes everything lol