According to this apple technote, there's a new feature in 10.4.9 which puts a delay on the Eject Key to prevent accidential ejection of media.
Now how silly is this? Why do you need to prevent something which isn't a problem at all?
What happens when you accidentialy press the eject key? Well, a CD will be ejected. So what. You can always just pop it in again or press the eject key once more.
This is such a silly feature i would have only expected to see from Microsoft.
Will Leopard maybe contain a feature which puts a slight delay on all keys on the keyboard in order to prevent accidential typing? ;-)