No.
XEON MPs are a slightly different flavor of the XEON processor - more cache, some architechture differences to make it more hyper-parallel compatible (more than 4?8? processors).
I'd believe that they are different enough that the MPs wouldn't work in a standard Xeon dual/quad/etc MOBO.
I could be wrong, but that's the impression I got from the little I've read about 'em.
FWIW
Scott