The A300 is still in production with its freighter version, many of which are currently being delivered to UPS and FedEX may make a large follow-up order for the aircraft. The current A300 is the A300-600R. From my understanding, the A310-200 is out of production, and the A310-300 will be produced by Airbus on a "special order" basis (whatever that means, aren't all aircraft special orders?) Further orders of these aircraft are not likely, unless a particular airline wishes to add another of the type to an existing fleet. Airbus is currently studying the A330-500, which is basically an A300 type with all of the updates and advances made in the A330 (I know its not that simple), including the common cockpit with the other Airbus aircraft. The development of this plane is likely to bring A300/310 production to a final end.