Additional "Order Produced" emails

It would be very helpful to be able to have multiple "Order Produced" emails available to send out similar to "Order Shipped".  Their Usage can be linked to the Shipping Method the same as Order Shipped messages.  We have various ways for orders to be picked up and/or shipped and many times when being picked up manually by a customer we don't mark orders shipped until they are actually picked up.  This helps to keep track of orders ready and provide invoices at the time of pick up.