Yeah, but non-developers who manage to install iOS 5 probably haven't actually signed the NDA.

The funny thing is as a developer you're not even allowed to mention in your description that something in your app is broken on iOS 5, since that would be breaking the NDA.

Apple also doesn't like it when you fix an issue, release an update and mention that you fixed a bug which affected iOS 5 compatibility. I needed to change it say "compatibility fixes for future iOS versions".