In light of the Lexmark decision Apple can't stop others from being interoperable legally. Their choices are to bludgeon clonemakers with frivolous lawsuits and try to bankrupt them for pursuing their rights, or to keep trying to make OS X paranoid about what it's running on while clonemakers keep patching the code that does hardware checks. And clonemakers might even be able to sue to stop Apple from doing that.

See http://yro.slashdot.org/article.pl?sid=05/06/07/1416228