Remember how the system we envision works though... the second you accept that transfer it's final. Until you accept he could change it. after you accept it's done and finalised.
Ok, so what you're saying is you are considering implementing what they call Authorize and Capture? If we can Auth when the order is placed, and then Capture when we ship and there's then no chargebacks after that, then we're golden! That's a very good layer to add to Bitcoins.
Beyond that, we'd like to be able to refund the customer (at our discretion of course), so add a way we can send the Bitcoins back to whomever sent it.