I think people are missing a central point with Ripple.

It's sold as a way to transfer USD or JPY or BTC or any store of value. It's not.

It is a way to trade IOU's, that rely on your trust in the entity that issued them. Those IOUs could be called RippleUSD or RippleJPY...but they are not real USDs or JPYs. Those real-world currencies are fungible: "freely exchangeable in whole or in part for another of like nature". One gateway's USD IOU will be better quality than another's; they are not interchangeable. They are not fungible.

Could be useful for internal purposes for banks, corps etc, where of course both ends of the transaction already trust each other.