KnocK thurrott for other things, but he's been on Microsoft's case about this before it happened, whilst it happened and after it happened.
He provided in his blog workable work arounds, and whilst a little hackey, worked. The annoying thing is that they're not honouring the licenses as properly valid... It was annoying at the time, but it's better now - adecent google or twitter ask and you'll get the solution. the price of the upgrade (as a fresh install) wasn't too bad for a VM XP user.