My prediction (and hope) is it ushers an era where consumers expect to have the ability to install any application they want on their mobile device, without having to go through their carrier to do so. I think carriers will start to lose that power and Apple will drive the change.
The best solution is still to stay off deck in the sense of offering a WAP-based web application rather than something that is installed. But this obviously wont work for some type of applications (Loopt is one of them). Loopt is doing great though, I am excited about their success.