Although prototype controllers provided to testers as part of the company's 300-strong US-only closed beta came with a set of four buttons in the centre of the controller, Valve's official design included a clever multi-function touch-screen portion which it promised would appear before the controller's retail release. Sadly, it has now backtracked with the decision to remove the touch-screen portion altogether.The news was broken during Valve's Steam Dev Days event late yesterday, with Valve claiming that it was removing the touch-screen portion of the controller as a result of its recent implementation of 'Ghost Mode.' Designed to offer yet another means of flexible control from the pad, 'Ghost Mode' allows the user see his or her thumb outlined on the screen while prodding the central touch-sensitive surface. This ghost-thumb can then be used to highlight virtual buttons - a fact that Valve believes renders a dedicated touch-screen pointless.An additional change to the controller's design announced during the event is a shifting of the face buttons, currently found at the corners of what was to be the touch-screen area, into the diamond-like configuration favoured of existing console controllers including Microsoft's Xbox pads and Sony's DualShock family. The company also hinted at the possibility of including a digital direction pad, but warned that a final decision has not yet been taken.For those curious as to the redesign, attendee Leszek Godlewski snapped a shot of the proposed altered design, which includes a pair of diamond-shaped face button groups - one of which would double as the digital direction pad - and a hidden touch-sensitive area where the touch-screen was originally planned to be, and shared it via Twitter