It seems that the same BIOS is used for either DX38BT and DX48BT2 which makes it look that they are indeed the same board, only best binned will become X48.
Like i said before, we'll all have X48 boards soon, I hope. If they use the same BIOS for both we'll have access to all features of DX48BT2.
BIOS 1507 is required for both boards. This means DX48BT2 is ready.