I dug up some more info on the case and it looks like a donor BIOS exists.
According to:
http://www.hexus.net/content/item.php?item=4202&page=3
Intel E7525 Memory Controller Hub supports Paxville DP, but also Nocona, Irwindale and LV Xeons, too.
According to:
http://www.itema-pg.com/Promo/2008/DELL%...670_en.pdf
The Dell Precision 670 Workstation also uses the Intel E7525 chipset and supports up to two 64-bit Intel® Xeon® dual-core or single-core processors with 800MHz front side bus and 2MB L2 cache per core.
According to:
http://en.wikipedia.org/wiki/Dell_Precis...orm_factor
Only some Dell Precision 470/670 units support dual core processors, (system board designations MG022 or XC837), very few systems actually supported Dual Core "Paxville" processors.
Finally, according to:
http://en.community.dell.com/support-for...09369.aspx
Updates in the Dell Precision 670 BIOS rev A06 include support for processors with more than one core and level 2 cache.
Thus, the E7525 chipset will work with the "Paxville" and a bios containing the CPU microcode exists (namely the A06 version of the Dell 670).