Sure they will have problems related to this.
Wait until Microsoft decides to make everyone revalidate their OS loads. You know there will be a screwup or three in that process so people who legally bought the OS will end up being denied full operability of it.
I wish I could post the eweek.com story I found.
There are snags in everything, though. For such a wide-scale implementation, WGA went over pretty well in a technical sense. Everyone complained about it, but there were precious few "WGA killed my Windows XP install" complaints. Which is pretty remarkable, since we're talking about Microsoft here...