Dual-layer recording question

Is dual-layer recording possible on current DVD burners?

I know there are no dual-layer DVD recordable discs at the moment, but if they were to become available sometime soon, would the current generation of DVD burners (eg. DRU-510, 1300A) be able to burn dual-layer discs or would the hardware need to be upgraded? Or do you think it would be possible to add that functionality via a firmware update?