My thoughts are when MS finds a pirated copy of Windows XP they just disable the ability to upgrade to their new service packs or ability to download updates. I think this is a great strategy because if you're a pirate or whatever you know why your PC doesn't work, but if you bought your PC from the local shop and it says your software is pirated, you know who to come back against. Now if MS took the same action as OzX is then they'd just remove Windows XP from your hard drive. Technically your PC is still there and it's still the hardware you purchased, how many people would go ballistic claiming MS ruined their PC. This is no different than the law congress was considering claiming they would allow the RIAA and MPAA to destroy your pc if you didn't delete mp3's or movies off your hard drive.
Now if OzX wanted to really do something I suggest going with the giving the customer fair warning repeatedly their chip is a clone or whatever but allowing them to use a stripped down version or whatever of the XOS. Better yet why not skip the chip making process and license the whole deal to cloners, apparently they can do comparable for cheaper so why not let them deal with manufacturing and selling and marketing and whatever else when you can sit back and rake in the money for nothing.
Finally, there's no surefire way to beat the cloners, I definately see unofficial XOS updates on clone web sites in the future w/o the chip disabling technology.