Ernia hit the main points, HW-side; the 4-pole connectors work fine with 3-pole cables, the mic input is just shorted to ground that way.

SW-side, it does work in Skype. There's been a couple of solutions rigged to use BT headset's button as some sort of media control, and I believe one of them worked with (or has been adapted to work with) the wired headset's button as well.