I like the out of the box thinking but I don't think it's feasible nor necessary. The bandwidth of the wire is not the reason the data transfer is slow and by the time the bottlenecks exceed USB 3.0 speeds in the iPhone we'll probably be well past USB 4.0.
Why would you want them elsewhere? I love the headphones on the bottom. I've been wanting this since the Touch first got it. No more cable getting in the way or my display or camera lens.
It's from January, but that is all addressed here: http://www.anandtech.com/show/5425/why-thunderbolt-wont-come-to-the-iphone-anytime-soon
The problem with that article is that it doesn't address how other devices connect to Thunderbolt. There has to be an Intel-based system with TB but you can connect to cameras, displays, external drives, etc. and non of them are running Intel CPUs in them. This means that Apple could have the same local controller on their devices that would convert the signal appropriately if it's connected to a Mac or a WinPC with Intel.