>> "We're expecting new software, but that's easy for Apple to keep under wraps as it doesn't really have to be used outside Cupertino"
I would assume they have to use iOS out in the field to test things like Maps and any changes they've made to the software controlling the radio signals.
Testing it in the field without detection is quite easy to do in the Valley. It's not like being in SF or NYC, where you could always have someone peeking over your shoulder.
Historically Apple software hasn't really been leaked that much as far as I can tell. The fact we don't know anything about iOS 7 or OS X 10.9 isn't anything new, that's the same as every OS release.
I would assume they have to use iOS out in the field to test things like Maps and any changes they've made to the software controlling the radio signals.