Nathan Marius

People seem to be missing a couple of points here--one, there is simply no way to limit it to "one phone." Once it exists, a judge can order Apple to do it again--and can do so in secret, so Apple has to do it without telling anyone.
Second, this isn't limited to the U.S. Once this exists, China could order Apple to do it routinely, and Apple's only option would be to leave the huge Chinese market completely. Apple's only defense right now is that the software doesn't exist.