[mebassett]

I would treat them as totally different things. There is a Category of Sets, but a Set of Categories would be a bit harder to define. So axomatic set theory could be a specific case of category theory, I suppose. But you can probably do a Class of all categories. (A Class is sort of a set-theoretic way to get around Russel's paradox, incidentally, you usually use a Class to define categories, so...) Though that's actually quite an irrelevant point. It's a completely different language for describing mathematics. I think describing category theory as an alternative foundation for mathematics (you really mean topos theory here) is a bit of an exaggeration. it's technically true, but most mathematicians I know are using it as a powerful device to prove things in algebraic topology or geometry, etc.