Asus and Gigabyte aren't the only ones sticking 6Gbps Serial ATA and USB 3.0 controllers onto P55 motherboards. Images of an unannounced MSI P55-GD85 motherboards featuring both kinds of next-generation I/O have appeared on the Coolaler forums.
From a distance, the P55-GD85 looks like just about any other high-end P55 mobo. The photos show a pair of PCI Express x16 slots, four DDR3 DIMM slots, heatsinks on the power regulation circuitry, and a few overclocker-friendly buttons on the circuit board (including power, reset, plus, and minus). MSI has also included little headers to let tweakers check CPU, memory, and chipset voltages with a multimeter.
We can see two upright 6Gbps SATA ports near the chipset and a couple of blue USB 3.0 ports in the I/O area. MSI has hooked up the controllers powering those ports to a PLX PCI Express bridge chip, as well. The automated translation doesn't explain its purpose very well, but on Asus motherboards, a similar bridge consolidates four half-speed PCIe 2.0 lanes from the P55 MCH into two full-speed lanes for the next-gen I/O controllers.
Other features on the P55-GD85 include eight power phases, dual Gigabit Ethernet, FireWire, and Realtek ALC889 onboard audio, which supports on-the-fly Dolby Digital Live encoding. The Coolaler forum member who posted the features doesn't quote a release date or pricing, though.