In London, we've had a setup for licensing 'mini-cabs' for almost a decade (and they've been around for far longer than that). In essence, they are all registered and regulated by a central authority, in a similar (but much less strict) way to London's famous black cabs. The difference being that mini-cabs are normal cars, that must be prebooked.
In that sense Uber fit right in, they're just another (one of 100's, if not 1000's) mini-cab providers. So for us in London, Uber hasn't really been revelatory at all except in the app driven aspects of their service (which is great).
There's always been a tension between liveried cabs and these 'mini-cabs' in London, and that's something that's been really interesting to see played out in different markets in the US. Especially when it's tied to the more prevalent laissez-faire attitude that the US has to market regulation.