Edit : For some reason I can't reply to posts so I'll do it here.
RiderOfGiraffes> It would will leave in question those problems in NP, but not NPC. Currently it is generally believed, but not known, that factoring is such a problem.
This is exactly my point. P = NPC doesn't imply anything about factorisation. Since factorisation is in NP we haven't shown that P = NP
kd0amg> NP-complete problems ... are, in essence, the hardest problems in class NP.
From what I understand they a 'thought to be' the toughest but this isn't proven. If this article turned out to be true then they are reduced to being as hard as P. So who is still standing as a contender for the hardest problem in NP? - factorization of course as it has never been demonstrated to be polynomially reducible to NPC.