The receiver of fiat IOUs needs the services of a gateway to receive fiat, and they must pay a fee. But it's the same with Bitcoin. "Competitive" BTC to fiat rates today provide poor value to the consumer.
If Ripple becomes the new platform for the "businesses that offers currency conversion", costs will be slashed for exchanges and gateways and rates will be much lower for everyone.
You could send your cousin in Mumbai rupees directly to their Ripple wallet paying virtually no fee. Of course, they'd have to pay a fee to get their rupee IUOs out of the system. But on the whole, the fees would be much lower than they are today.
Bitcoin can only work to supplant other currencies slowly over time. It will be a long process. Bitcoin = apples, Ripple = oranges imo.
Right. But there was no reason for Ripple to base its transaction system on UNLs and consensus. This transaction system is just inferior to Bitcoin. They could have easily used the Bitcoin transaction system (ie. hashcash/proof-of-work) to record all transactions in Ripple, but they chose not to... instead we have to rely on "trusted" nodes in order to fend off sybil attacks. If people find the Ripple gateway system to really be a benefit, I think it would make sense to build it on top of Bitcoin protocol. As far as ripples (ie. the coin)... that seems to be just another currency with an inferior transaction system.