For automated market making purposes, an API-directed withdrawal facility (such as the Mt. Gox send_simple function) would be very handy. Does such an operation exist now? If not, do you plan to add one?
No. Such API function would expose a security risk. One possible solution would be adding a function which sends to already predefined, confirmed address (via two factor authentication, at least) which can't be changed using API.
That's a great solution. I agree that Mt. Gox's send_simple makes me a little uncomfortable.