Seems like a decent business idea. Someone like Sedo should do it since they have their own accounts at all the registrars and can have both parties transfer names to them and get them both in their control before doing the swap.
I would not trust doing a swap with someone at zuho.com. One person can always screw the other, and there don't have trader ratings like here. In fact, this forum should start a "Swapping" forum and charge something like $50 for doing the esrow for people.