Why does taking a screen shot require root access? I was thinking about this and I don't understand the reasoning behind it.  iPhone users have this capability out of the box, and yet Apple is far more protective of their devices.

Whether this turns into a philosophical discussion or a technical discussion (or maybe both) I'd still like to understand why this limitation exists in Android.
No idea why it wasn't available before, but as of 2.3.3 non-rooted screen shot support was added for system apps, at least. As eldarerathis noted, there are some articles out there implying that this would let any app capture a screen shot now, but according to an android engineer this permission is only granted to apps signed by the system image's keys - it is only available to be rolled into the OS, not as a feature 3rd party apps can access.