I'm not sure about that. After the Mosaic debacle, I've had a couple of orders that were charged a week after ordering, and then another ten days later I got a refund, and I still believe that the item listed was never really in stock with the vendors. I guess if a vendor just tells Amazon to charge, they do so, regardless if the vendor actually has shipped the item or not.
Here's more about the new Amazon Marketplace "Charge When Ship" program:
http://www.amazon.com/gp/help/customer/dis...8309&sr=1-3
Not sure it applies to all sellers yet, although that appears to be the goal. Also, I think you're right that it's still dependent on the accuracy of the sellers' reports to Amazon that the orders have been shipped. Still, it's definitely an improvement over the old system, and for the sellers from whom I've made recent purchases (Newbury Comics, Import CDs, etc.), it seems to be working.