I'm interested in this new version as well. From comparing pictures on Newegg, it looks like XFX is consolidating the 5858/5870 cards onto one board design. The board is slightly longer than an OEM 5850 board and slightly shorter than an OEM 5870 board. It has power plugs on the end like a 5850 and unlike a 5870. The fan is in the middle of the shroud and vents are located all the way around the shroud, suggesting that air might be pushed in all directions, not just out the back vents.
Haven't seen any reviews of these models yet, other than user reviews on Newegg.