P vs. NP resistant problems
According to Stephen Cook on wikipedia, http://en.wikipedia.org/wiki/P_versus_NP_problem
...it would transform mathematics by allowing a computer to find a formal proof of any theorem which has a proof of a reasonable length, since formal proofs can easily be recognized in polynomial time. Example problems may well include all of the CMI prize problems.
This opinion seems to suggest that if in fact P = NP, then even the most notoriously difficult problems in mathematics would be essentially trivialized. So I am wondering are there any problems that are resistant to becoming 'easy' even if P = NP? For example, according to Cook, none of the seven Clay Mathematics Institute Millennium problems is an example of this.