I downloaded the iOS 7 beta yesterday. I have to say I'm mostly unimpressed. Increasingly Android (HTC One or Samsung GN2) is my daily driver. I like that I have a choice of hardware screen size, design, build, etc.
With iOS 7 I don't see much new here except re-designed icons that the tech press has fawned over (a little embarrassing actually). If BlackBerry were to redesign their icons I guarantee there would not be nearly as much adoring praise.
Aside from iTunes Radio (whatever they officially call it) there's very little here so far that I find would make a compelling upgrade.
I think Apple does have to move slowly with their upgrades as they have so many users on the device that you don't want to shock them however this really seems to be a very slow progression.