The C drive is the top one and the D is the bottom, right?
I've seen them before. It drives up the price a whole £10 or so, and gives the advantage of allowing much quicker CD copying, as well as reducing disc swaps (particularly useful for games that require a CD to be present).I've never heard of such a thing in a standardized system; I would think it would drive the sticker price up too much without really offering anything likely to grab the consumer. But I suppose it's possible.