Supposedly there is no plans for dual socket 775 so for those specific chips, you're probably out of luck. For Intel, socket 771 is designed for multi-processor workstations/smaller servers. It seems Intel has made a much cleaner distinction between its desktop and workstation platforms in the past 6 or 7 years.
At this point, it would be cheaper to sell your current cpus and buy a Q6600 or wait for a cheaper yorkfield (Q9300 perhaps?).
Skulltrail will fit any Xeon 771 socket CPU or the new QX9775 which is also 771 socket...
Skulltrail also supports SLI and Crossfire, which no other motherboard currently does. mobo is about $600 and QX9775 starts at around $1400, then if you want dual your looking at $2800 for cpu's add mobo for $3400... now all you need is hard drives, GPU, case, RAM (ooooh its ECC RAM too) EXPENSIVE build needless to say