What about this one with a serverworks chipset?:
http://www.intel.com/design/servers/blades/sbx44/
Intel's white-box servers are a bit of an odd-ball, and they are sort
of an exception to the rule above. Intel does indeed sell 4-way
XeonMP servers using Serverworks chipsets, not only the blade server
you mention but also a rack-mounted and tower server as well. I
suppose you could say that they are offering a 4P motherboard with
these in that if you buy the whole server you get a motherboard with
it (of course it will only work in the Intel server).
I'm kind of guessing that these whitebox servers may end up
disappearing though, they don't seem to have succeeded at all in the
way Intel had planned. Originally it was supposed to be that Intel
would do the design work with these servers and then companies like
Dell and IBM would buy the whole system from Intel, slap their name on
it and sell them. However a few other companies beat Intel to the
punch and I'm not sure that any major vendor has ever offered an Intel
white-box server. Who knows though, they may still succeed. A couple
companies that have succeeded in this include MSI (IBM's x325 and x335
servers are both designed and built by them, and perhaps some others)
and Newisys (they designed Sun's AMD Opteron servers), so perhaps
there is room for Intel to compete here.