If you don't pay your phone bill it hits your credit.
If you have shitty credit you cant finance; get credit, loans, you can be sued, withheld paycheck ext.
The only way a system like this will work is if we somehow use the law to enforce contracts.
But I'm probably not the only one here that thinks; **** that
Pretty much this. Reputation counts for a lot, and I'm going to give a lot more credence to merchants and services with a history of being reliable. That's where I'm going to spend my bitcoins. People who develop a reputation for honesty are going to be attractive without some trusted designation by a third party.
I'm not even sure how much value there would be in certifying a bitcoin address as "trustworthy" because I'm not doing business with the address in isolation. I'm going business with a person or organization selling products or services. Other than facilitating payment, I don't care about the address.