Just had a weird idea. If a system like that ever developed (where people backed "vouches" with financial penalties) you could see professional "trust-bondsman". Say some new trader has no rep or little rep and he needs rep to get rep. So he goes to a "trust-bondsman" who collects some ID, makes some verifying phone calls, and requires the new trader to put up some funds into escrow (say 20 BTC). The trust bondsman may then offer x BTC of rep (will pay x BTC for a busted trade). The 20 BTC are just escrowed so later when the new trader has enough self earned rep he can collect his escrow back (minus a fee). Higher level of guarantee may require more extensive dox (mail verifciation, public records search, etc) and a larger escrow. In time the bondman may offer a higher x BTC on the same escrowed amount.
I wish a service like this existed.
I ended up doing something similar, just posted my info and created a trust account with a third party.
See the [Bakewell] thread for more details.