If we're talking about game controller design, I've always been partial to the gamecube controller. It does many things right - different shaped buttons on the button side, to better distinguish them and easier to remember which button does what, pressure-sensitive trigger buttons, octagon-gated analog sticks... The only thing I dislike about is the swapping of the analog stick and d-pad, I feel that the PS arrangement of having both sticks on the bottom is better and more intuitive.
Oh and definitely there needs to be a real d-pad, none of these cheapo x-box-style floaty things with zero accuracy, please.
Going by all the indications so far, it's going to be an xinput compatible controller, as that's what they are already using for big picture mode. E.g. Xbox360 controller or Logitech F310 will work. The selection of buttons will likely to exactly that.
Steam Box with HL3 exclusive on Linux and the console! Am I over-optimistic?
Whatever happened to half-life 2 ep 3? I seriously doubt they'll be able to live up to expectation with the half life franchise. There are many companies devoted to producing high quality linear fps's these days, and half life 2 (awesome as it was on release) hasn't aged well. I doubt valve can afford to limit their games to just their console (Which may well flop) and linux.