SMP systems?
If so I think they expect you to know the platform before building one

(I keed)
To answer you question, Not that I know of.
And new Xeon's are out, newer ones should be out later this month (based on the core arch). but non of them have a HT buss (they dont comunicate between CPU's like Opterons do) sooooo If your building a system with say 4+ CPU's It might be a good idea to stick to opterons.
Otherwise take a look at Woodcrest Xeon's (if its for personal use screw it and get a Conroe and OC it like crazy

)