The focus of many replies here is based on comparing Ripple to Bitcoin - but shouldn't we really be comparing it to Visa or Paypal?
Currently I have to have a paypal account if I want to send money to another person who has a paypal account.
It seems the point of ripple is that it allows us to pick our own gateway - the gateways do not need to be dependent on each other, we just need to trust our chosen gateway.