In my view the whole concept of supporting debt/transactions through trust is majorly flawed.
Why create a system that is based on IOUs and trust?....."faith"?....."credit"? <--- The last two words are use by the U.S. govt when making promises they can't keep based on IOUs.
We already have that type of broken system...it's called the Federal Reserve System.
Hey, Ripple Labs is the new Fed! They and sub-banks (Gateways) issue currency / IOUs, while Ripple Labs can play Federal Reserve and set Ripple-affecting variables like account reserve requirements, trust line requirements and transaction fees!