It's true, it's easier to steal with Bitcoin now and we really need a standard centralized escrow service which can "verify" vendors and buyers, something like paypal (I can't believe I said that!) Not for everyone to use but some will find it useful
A few weeks ago, I posted here for a similar system. Suddenly some of the senior users got ballistic and shouted me down. It will never happen. And Bitcoins will never become mainstream, unless such a system comes in to existence.
Trust comes from satisfied customers, but the only way to prove it is provide some kind of documentation - and in the process you'd have to trust the source of that data. Its a tricky subject, honestly - because at some point trust does enter the picture.
Not really sure how to tackle that other than someone you'd actually believe is an impartial intermediary.... but how do you vet that? Its like we need some kind of global karma/rating system that doesn't fall prey to vote-stuffing or other "gaming" behaviors. Periodic purchases that are published online with full information, to trap the scammers?
I don't know...