Valve has just released their big picture mode in beta form, now on PC (Mac beta coming soon). The new mode not only enlarges Steam for a TV you are sitting a few feet away from, it adds a whole new interface that'll make the whole experience much easier.
The new mode also comes with a built in browser and the new interface is designed to work with controllers. Valve has even created a controller tuned keyboard that looks to be lightyears better than anything on current consoles. Once again the big picture mode brings in to question if Valve will be creating their own dedicated console or entering the hardware business at all.