I applaud Asrock for this effort and it's really something up their alley, but in the end, it just seems a waste of money to upgrade to this.
Many people have P55 mobo's with usb3 and sata3. Are you really desperate to get pci-e 2.0 lanes from the southbridge instead of 1.1? Sure, you get native sata3, but do you really need that? Not if you're using a regular hdd or sata II ssd. Ok, you got a crucial sata3 ssd you say, well that might be a reason since they don't work optimally on some Marvell controllers. Although as an os drive it works fine if you plug it into the ich10 sataII ports. If you have a P55 mobo without usb3/sata3 you're probably much better off buying a separate usb3/sata3 add-in card.
But it's a nice idea and if you think it's a cool board, go ahead buy it. Otherwise the only real use I see is as a replacement of a dead P55 board and you want to keep your existing cpu.