All I see are USB 3.0 external hard drives. Are there other devices that will greatly benefit from this higher throughput? Are external hard drives the primary device that's pushing USB 3.0? If so, then I don't think there's much advantage for USB 3.0 for most consumers.
There is this USB 3.0 monitor for example. And I'd guess external GPU would also take advantage of it fairly well.
I think external GPUs will also be seen in times to come. A variety of portable notebooks now have CPUs capable of running high end graphics applications/games. In order to keep the portability we need good battery life and this means small screens and low power GPUs, however When these become external it will be an opportunity to replace the desktops we currently rely on.