There is no doubt that eBay will notice the effect of shipping charges the world over... and I think they just might work a deal with a carrier (or even a group of carriers; USPS and others) for special rates for items sold/purchased through their network -- since I seriously doubt they will be willing to take a hit w/o doing something.

Shipping costs is the number one topic out in the field; antique shops/shows/fleas... and people are getting fed up with the increases and eBay knows this. I seriously doubt they're going to sit there like a bump on a log and not do anything about it.