The new “Parental Controls”, formerly “Limitations”, provide ways to lock down applications for certain users, for example limiting which people a user can send email to.

10.4 now allows you to create “burn folders”, which the data in can then be burned to a CD or a data DVD.

10.4 can display quick slideshows of the graphics you highlight, by selecting “Slideshow” from the window settings menu.

Now this I thought was amusing.

After years of being able to control when and when not to remove media, Apple now has to deal with thumbdrives that can be yanked out whenever the hell the user feels like it.
So OS X now pops up this error message saying your data may be damaged, and that you should select “eject” from the menu.

Note that you cannot physically “eject” a thumbdrive.