Well, here is one made by Olympus, but you may very well be right about it just creating two channels. If it it didn't, the left and right are so close together that I doubt there would be much of a panning effect...not toomention the steep $49 price tag.
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no, they're genuinely stereo mics, with directional pickup. to exhaust my technical knowledge, stereo strictly means "solid", and in theory the mics have to be at an equivalent point to the playback speakers to get accurate stereo presentation, so not ideal, but a lot better than mono.
if you use a dummy head and put the microphones where the ears are, it's called binaural, and playback is of course ideal for headphones.
yamaha and others have some neat tricks using DSPs to transform stereo sound into binaural using "head related transformation functions".
--edit - oops, fixed