I'm fond of saying that Ripple is like Bitcoin for people who don't want to topple the government. If I'm still using dollars and euros in 10 years, I'd prefer to do it in Ripple. The feds should feel free to guarantee my Citibank IOUs, as they already do.
IOUs have to be paid. I'd rather trade with what I have so I know exactly where I stand. A person/institution can do a lot of trading through Ripple with NO financial investment, just trust. I don't agree with this principle. I still believe that if a large financial institution defaults then a lot of ordinary users will have their balances raided, just like what's going on now with QE. Institutions fail, people pay.