Just seeing this news today, dunno what to think of it. http://www.numismaticnews.net/article/undocumented-coins-at-risk
I don't know what to think of the article, either. I do have to ask about the title of your thread, "Ancient Collectors...". Are you speaking to very old coin collectors or collectors of very old coins?
I would be more concerned if it affected areas I collect more strongly. However, I do think articles affected by the ban will become disproportionately pricier here, like Magna Grecia, cypriotic, pre-Siculo punic Roman, etc. I think once their here I doubt the cops will be raiding anyones collections asking them to prove provenance. I still feel coins are different than antiquities, and I fully support their antiquities efforts, but to try to claim ownership of mass produced articles meant to be traded is ill advised.