The Barton is basicly a TBred with twice the L2 cache ( 512kb ) but lately the TBreds have been going on a 166 FSB.

AFAIK, the AMD-760MPX platform doesn't support such an FSB.

Will there be 133 FSB Barton CPUs or will AMD ditch the AthlonXP for MP platforms ?

The extra L2 cache in the Barton will most likely show the most benefit in a dual CPU system so I don't think AMD won't support that platform.

The Athlonmps also have a higher price premium compared to the same speed Athlonxp, which is another way of getting better profit per chip.

On the other hand, I think the 760mpx chipset is only a filler for until another company such as Via, SiS or even nVIDIA is willing to provide a dual CPU chipset itself.