Apple will soon require that all Mac App Store apps implement sandboxing, which forces developers to request specific permission (or, in developer-speak, “entitlement”) from Apple to give their apps access to certain parts of a user’s system.
I’m not sure how big a deal this bit will be in practice; I think Applescript is a fun but largely niche corner of the OS. The larger issue to me is that the rules are changing in an environment we’ve become quite used to. The evolution of the computer (or at least “thing connected to an external monitor and keyboard”) from the beginning has not drifted too far from the notion that the owner can pretty much do what they like with it. Sure, the iPad and iPhone and assorted other devices have changed that, but those are new devices and form factors.
I look at it this way: with the IOS devices, Apple asked us to sign a new contract. This is how these particular devices work, and these are the limits of your interactions with them. With each new revision of MacOS X, Apple is attempting to renegotiate an existing contract, line-by-line. Don’t be surprised when Microsoft follows the same path.