Before too late, I'd suggest to conduct a little discussion on how we actually want it, and whether we want it at all. CHDK PTP, that is. In other words, to formulate a standard if you wish. Does CHDK PTP go into the mainstream, or only remains in personal builds? If it makes it to the trunk, then in which shape? Etc.
(My personal point of view is pretty close to mweerden's: I'd suggest his well-documented implementation to become standard, with small modifications on both the camera side and in ptpcam. Note that ptpcam is easily portable to any platform, and that the basic implementation on the camera side only requires one function address.)
