It is meant to be used with a controller instead of a mouse and keyboard. Probably a better version of Steam's big picture mode. They are essentially targeting the console market by making PC gaming more simple like a console so you can just grab a controller, sit back on your couch, and play on your living room TV (or bedroom TV or anywhere you have the thing hooked up to. It wont be solely for those types of cenarios. For example, if you wanted to make SteamOS your main PC OS then you can use it just like linux with steam installed and the core OS will still be tweaked for gaming and whatnot and you can do all the normal stuff like browse the web, write papers and emails, etc.