I'm waiting for some reviews to go up before making my decision..
Historically, I'd go Asus or Gigabyte; I was leaning toward Gigabyte, but it seems the UD5H switched to a pair of Marvell controllers for extra SATA, and also a VIA chip for Firewire, which may cause problems.
A friend of mine has an Asus board with the Marvell controllers and he had a lot of issues getting hotswap working reliably on it. My mobo with JMicron controllers were pretty flawless. As well, my Firewire DAC recommends only using TI firewire controllers, so we'll see. :/
Unfortunately, even with mobo reviews, I have no idea on DPC latency, so that will be a shot in the dark.