Great ideas but HTC beat you to the punch. A couple of years back, we did something like this also.

To be honest, I wanted to make the slide in left, then thr Left and Right buttons would be kind of annoying  for users that use right hand. When I've seen this ( image down ) , I've got the BIG ideea

(yes is HTC s730, big brother of the phone you've said )

 Now, about the controller: the 4 buttons are like all consoles gamepads, but the A B X Y combinations are changed

 Until now, GamR' gaming keys (ABXY) are different fron all the consoles out there.

 (I have to admit that GameCube's gamepad looks intresting /// would be great for Asphalt or Bounce N-Gage, the big A button ...)

 Here is a little update

 I've had in past an mo to e398 . I liked it very much becouse had ritm lights. (Not such a big invention, but looks great)

 And in dark.

 What if the Left and Right buttons to be like :

  When someone calls or you listen music or the alarm, to see nice cool lights.

  Also here is only an ideea: When is in Phone mode, the left and right  should pe "pressed" automaticly in, and when you slide the phone, the left and right to be unlocked and go outside and be able to press them . (This is ONLY an ideea !!!)

 In this way, you can say for sure that from a SmartPhone, with ONLY 1 slide you have a gaming console . (2 in 1) .

 something like gaming handheld console in disguise