Atom based blade servers
With power and cooling being a larger and larger part of running a server farm I would think that the Atom processor would be a natural fit. Half the CPU power at a fifth or a tenth of the power consumption would be a win. Build a 2U blade server with 2 or 4 CPUs per card. Each CPU would have 4 Memory slots, some sort of fast flash slot and maybe a 2.5" SATA connector with the disk mounted on the blade board itself. No South/North bridge, no other stuff. I suspect that an Atom CPU with the OS and applications running in 4 Gb of RAM and no local disk would scream. Put 4 of them on a blade, put 10 blades in a 2U chassis. I think the cluster people would be excited. You don't get a lot with each core, but there are so many of them.