Jobs' confirmation of an existing "kill switch" sounds like a technical counter-measure to me: http://www.telegraph.co.uk/technology/3358134/Apples-Jobs-co...
The recent patent submission to track 'suspicious activity' seems like a nice detection system that can be used to flip the kill switch when kids try to segfault the iOS, in order to find an attack vector for a jailbreak.
I think Apple may be keeping the status quo for a while longer, to secure it's position in the smartphone market, to avoid a backlash, to benefit from free vulnerability disclosures by the jailbreak community and to focus it's development efforts to more important tasks at hand.
Apple is indeed not openly fighting jailbreakers, but it's in their interest to keep the software under control. Whenever you upgrade from a jailbroken phone, all the unsigned apps disappear, along with the data contained. Given their desire to control the application ecosystem (grossly benefiting from all the developer signups and app sales), if the percentage of jailbroken iPhones ever becomes a blip on the radar, they will take repressive action to disincentivize the user (AppStore lock-out, kill-switch) and jailbreak tinkerers (suspicious activity reports).
I don't find the unlocking US phones in Europe a problem, because legislation here often requires the phones to be unlocked from the subscription plan. iPhones can be bought unlocked at a slightly higher (unsubsidized) price.