still this is a dumb move for Microsoft - if you have the freakin' license and it is on ONE computer, who cares whether it is gets moved to another computer? Seriously, I think it is just another money-making scheme
Making money is a bad thing?
Seriously, I think this is for supportability purposes. An OEM copy of Windows has no support from Microsoft, the OEM does all support. So if you move the license to another machine, potentially one from a completely different OEM (or a homebrew box), who will support you now? Not the OEM, and not Microsoft.
There is a reason why the OEM copy is so much cheaper. I'll give you hint, it has nothing to do with the packaging. Given how most people in the 'enthusiast' crowd (who are the majority of people building their own boxes) drop 400-500 bucks on a video card without a blink, I don't understand why people try to save money with an OEM copy from newegg that essentially comes with zero support. The OS is usually a very small percentage of the total cost of a home built machine.
But there is really nothing to see here. The majority of people with OEM copies of Windows have no intention of swapping motherboards. And those who do intend to be swapping motherboards should be buying the retail version.