Had the same argument about a year ago. No, once you override it, it's gone. The value of the font-family property is a single list, not a list of lists.

Example: http://i.imgur.com/8TLBd.png

It doesn't work with inheritance and it also won't work if the very same selector is used. E.g. if you add:

    .comment{font-family:foo}

to the current stylesheet, you'll get Times New Roman (or whatever your browser's default font is.)

Hence this line:

http://www.w3.org/TR/CSS2/fonts.html#font-family-prop

"Style sheet designers are encouraged to offer a generic font family as a last alternative."