Well I know that the standard transistors that intel used before the 3-D transistors, were ok with extreme cooling, but with the new transistors could the material properties of the silicon-on-insulator substrate change enough to hinder normal transistor operation? I haven't seen or heard anyone using LN2 for the sandybridge.
~currently building another LN2 generator, to supply the system constantly to support long term cooling. With proper design i should be able to avoid most of the condensation (hopefully anyhow).
If a straight liquid nitrogen cooling is not viable, I'll just do a solid water cooled system, which would be cooled by LN2. Possibly not use water but a gel of some sorts...
EDIT: I should add, this would be for GPU, CPU, Northbridge, Phase transistors and anything else that gets hot.