I think MS is just testing the waters and attempting to push the limits, hinting that they plan to nudge-out OEM licenses in the near future. That would be a shame, because big manufacturers like HP and Dell could, in theory begin to charge more for their machines if they attempt to secretly collude.
MS knows this won't fly, and would create bad press if forced. They just want to scare people.
What they really need to be more concerned about is piracy. Nearly everyone pirates here in Asia. I actually had a difficult time purchasing a legitimate copy of Vista for my wife's computer, and even it had been opened.
If MS puts these draconian OEM ideas into place, piracy will be encouraged, as will other OS's.