I have always liked the price/performance offerings from AMD, and at work all our machines are running with AMD processors), and am usually promoting the performance points to my friend(A die hard seemingly unconvertable Intel fan). After much reading on thermal solutions, and the reading of this article, I can see why IBM uses Intel processors in their servers, AMD CPU's run much hotter then Intel processors(or at least P3's, I'm not familiar with P4 power dissipation), and can be counted on to respond positively to unlikely circumstances(heatsink falls off, fan stops functioning).
Learning about different AMD cooling solutions, I can see another reason why AMD processors need to address the issues with processor heat dissipation, and integrated thermal overload protection, heatsinks are much larger then Intel equivalents, and many are more complex to mount(the original version of the Swifttech MC462 had difficulty being mounted because of the size of the base), this could possibly cause someone who is building up their first system to mount a HSF slightly incorrectly, lose a processor, and/or mainboard. Sure we are all smart enough to see when the heatsink isn't sitting right, but not everyone has mounted their own one before.
Redundancy & Reliability is what differentiates a server from a home machine, I don't believe IBM would be making any money in the server market, if everytime their Processor cooling solution failed, there was a chance of the processor being destroyed, which in turn could take out the mainboard, and possibly damage the RAID card(and so RAID configuration) attached to the dying board/processor.
So far I can see the MultiProcessing solution offered by AMD working on workstations, but I have yet to see a brand name Server(IBM, Compaq, etc) use an AMD processor. I like AMD, and will most likely buy myself an AMD machine within the near future, but if AMD wants to make brandname server machines, they have a lot of processor tweaking to do.