On: Psystar releases the software they use to install MacOS on non-Apple hardware

It would be hard for them to "sneak" a gigabyte of software onto someone's machine, nor would it be ethical or sensible.

It's 'lite'! Perhaps they can whittle it down to the same ~100MB that some of their iTunes+Safari+QuickTime updates approach.

And Apple has used their updater to push software people never consciously chose to install. See most recently:

http://blogs.zdnet.com/Bott/?p=1349