The Inq reports the new AMD has once again renamed an old product rather than introducing a new one:
The RV 515 and RV516-based X1300 have been given a new name. From now on you will know these cards as X1550. This suggests that the card is not quite X1600 performance, but it ought to be better than the current X1300.
Well it's not. It is just a renamed product, which sounds better and looks good on the box. That’s it. If you see one of these cards, beware, as you are buying X1300 generation of card.