Ok, I have read up on all this until my eyes have started to bleed.
My home build is ready to go but I need to make the final MOBO decision. Building a 955 based system. mainly multimedia and gaming. Likely Crossfire in future.
Here's what I got....
Gigabyte GA-790 XTA-UD4... Has 3.0 USB and SATA III. Highly rated! Good combo deal. OR......
ASUS M4A89GTD PRO... New 890 North bridge. Also 3.0 USB and SATA III. Apparently Phenom x6 able.
GIGABYTE GA-890GPA-UD3H... Same stuff as above different company.
All are about the same price. 890 boards have possible better future as AMD stated compatibility with new Phenom x6. BUT, the boards are new with possible first edition bugs. VS.. 790 based board.... well received and excellent reviews. MAY??? have Phenom x6 capability??? Don't have a clue about Gigabyte vs Asus choice... seem almost identical.
The 890GX based motherboards are six core ready, a BIOS flash might be required though. I'd get the ASUS M4A89GTD Pro w/USB3 personally. If you're not too concerned about upgrading to a six-core though, I'd just get the Gigabyte GA-790XTA-UD4.