iOS 5 makes that lock screen more useful and interactive. Notifications are listed in the lock screen (useful) and you can interact with the app that issued the notification - listening to a voicemail, for example. That allows someone more access than just making an emergency phone call. Apple hasn't yet been clear on the level of interaction that will be possible with non-system apps directly from the lock screen, but it opens the door for corporate information to be divulged even with a passcode policy in place. Even if it's just hearing a voicemail, that's troubling.
Similarly, the camera can now be accessed while a device is locked without entering a passcode. This is less troubling, since only snapping photos is supported. You can't access existing images or send new snapshots. But again, there's some cause for concern since it provides unauthenticated access to a locked device. One scenario that came immediately to mind involves an employee who surreptitiously takes incriminating photos of some sort using a coworker's iPhone. The employee then reports his co-worker for stealing company data, the iPhone is searched.... You get the drift.
I'll admit these aren't the biggest concerns, but they are situations that I hope Apple addresses using extensions to the existing device management capabilities.
Scratching the surface
One thing seems clear after this year's WWDC keynote: We haven't seen everything that's coming. Apple was very clear to note that we only saw demos of 10 of the hundreds of features in iOS 5 and in Lion. With a huge number of user features being rolled out this year, along with an incredible number of new APIs for developers (1,500-plus for iOS 5 alone), I think it's clear that Apple still has some tricks up its sleeve.
For enterprise customers, tricks and surprises are rarely good things, but that's the way Apple works. And like it or not, Apple is a driving force in today's mobile industry and in the so-called consumerization of IT. That said, I'm optimistic these will be largely good surprises.
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