I'm looking for a high end dual i7 2600K Motherboard, for video production? Apple has a Quad-Core, Octi-Core and 12-Core, then why can't we find the same for the PC? The new Sandy Bridge chipsets are required for my software.
No such an animal, you're comparing Xeon with 'current' Sandy Bridge CPU which lack the dual QPI that are found in the e.g. LGA 1366 or the coming soon LGA 2011. IMO - if you can wait until November then get the new LGA 2011 with Xeon E5.
The OP is clearly referring to the Mac Pro and current are using only Xeon CPU(s) -> http://www.apple.com/macpro/features/processor.html particularly if you see 8 or 12 cores listed it's a Xeon or Opteron. I have a Mac Pro and I thought I already stated 'Xeon' above