Will your microwave wipe away your tears and tell you it’s all going to be OK? No, that's what your friends are for. Your microwave will, however, help make the experience of cutting onions less emotional. Simply microwave your onion for 30 seconds and you'll see that your peeling and chopping will no longer induce tears.
Disclaimer: I don't know if this actually works or not - I haven't tried it, but I was sitting in the waiting room at my doctor's office yesterday and read this in a magazine.