Of course, you could argue that the platform cost for AMD's Athlon MP is lower than Intel's Xeon, but according to this story that's not always the case:
One systems integrator tells the INQUIRER that a Tyan Thunder S2469GN ThunderMPX motherboard, supporting Dual AthlonMP, Ethernet, GigE, and video costs $378 USDThe Inquirer also suggests that Tyan will not be making any new MPX-based motherboards, which is odd, because AMD started the whole dual Athlon party with Tyan.
Meanwhile, the Tyan S2722GNN – a dual Xeon motherboard, using the i7500 chipset, supporting 100/1000T, video, PCI-X costs $298 USD.
As Xeons ramp past 2.8GHz, Intel will be well-positioned to steal market share away from the Athlon MP. A few enthusiast-oriented i750X-based motherboards would certainly help Intel's cause, and those motherboards may materialize if manufacturers shift their attention away from AMD's neglected dual processor platform. Hammer is, of course, coming, but for the first time I'm wondering if dual Xeons could become a reasonable option for PC enthusiasts.