Not that I know of. Since the other side would be covered by the socket and pcb, it would take special computer engineering skill to make one. but then again, it would introduce more dust into the socket region where the proc and the mboard will meet and we wouldn't want that
I don't think that's possible since the pins are on the back of the CPU so there would be nowhere for the heat to contact with the heatsink. Also I have always notiecd that there is a lot of complicated circuitry right under the CPU so they couldn't just cut a hole there so easily.