I have been using SteamBox since it`s beta and love it. I can sit on my couch and load up multiple games in one session and never have to use my keyboard. I will get Original Sin no matter what but being able to play from my couch would be icing on the cake.

I also think the FULL CONTROLLER SUPPORT mark on Steam games has become a selling point for many shoppers. If you want to pull in more customers from the console crowd (which is what Steam is doing with SteamBox) you will need controller support.

A warning though as other have pointed out. Leaving your PC crowd behind is a mistake. Having two separate UIs would be a lot of work but I think it`s the only way with such a detailed game world. If you are going for controller support go 100%.