This is not going to end well for eBay, I can see it now. Some fake items are surprisingly good, you'll be reading stories of people being ripped off because valets were told they were given designer brand items only for them to be discovered as fakes later on. Somewhat cool idea I will admit, but when you're dealing with e-commerce and allowing users to get other people to sell their items, it'll open up a rather complex wound.
It's a new implementation of a common service. You have a point with the auction house providing the service it blurs some lines. Similar points have been brought up regarding some of Amazon's services. I think it will rely on eBay's willingness to shutdown bad vendors (something they aren't known for at the moment).
