Except -- and this is really fun, thanks, Apple! -- I believe the current OSX build will no longer work as a screen saver on MacOS 10.6. It will work on 10.5, and 10.7+, though. That's because 10.6 was the one and only version of OSX in which ScreenSaverEngine required .saver bundles to use garbage collection, and the latest release of Xcode has dropped support for emitting GC-optional code entirely. So I can no longer compile a version that will run on 10.6.
Also apparently the new app-store submission process requires that you set the minimum iOS version to 5.1.1 or newer if you want to include a 64-bit executable at all, despite the fact that the 32-bit executable runs just fine on iOS 3. Thanks again, Apple!
Enforced obsolescence. Ain't it grand?