Well I have the realtek audio and lan on my new MD. The audio just works, however, the lan gave me a bit of disdain, but it was short lived. You can see what I had to do here with the realtek gigabit lan -
http://wiki.linuxmce.org/index.php/R8168#Asus_M3A78-EMNot a huge issue, and if you are in luck, it will use the same driver, I already have compiled. But worth a looking at anyhow. Looks like a sweet board, dual lan, spidf, 2 pci and 2 pc1 1x and a good pcie for an nvidia card.
Best of Luck and Regards,
Seth