...to speed up/cheapen the money-transfer process, we need to get away from using traditional banks entirely.
The solution is not to make the process of converting to and from fiat faster and more decentralized, but rather to "close the commerce loop." It shouldn't be necessary to deal with fiat at all. This is done by growing the Bitcoin economy of goods and services to a sufficient size that someone can stay entirely within Bitcoins or IOUs without the need to deal with fiat.
Sure, but how do you get lots of people to do that? Bitcoin still scares away a lot of people, because of (1) its price volatility (which is a consequence of it still being fairly small), and (2) its association in the media with "unsavory" activities (Silk Road, etc.) - which also is a consequence of there not being enough "legit" activity in BTC yet to outweigh the prominence of the scary stuff. Until it's bigger, most people won't want to use it. So growing the BTC economy is an uphill battle.
One nice thing about Ripple is that, even without making deposits through a gateway first, as long as you have XRP, you can go ahead and start creating your own IOUs that are denominated in whatever your favorite currency is - this avoids both of those worries. It thus may be a more attractive "on ramp" to the world of digital currencies for many people than Bitcoin itself is. Once they get used to using Ripple, they may be more inclined to try out things like Bitcoin. Think of it as training wheels....