A lawsuit? Really? While I can't verify the server Snow Leopard page due to it not being in the archive, the client page had "All features on this page are subject to change." at the bottom. Even if that wasn't there, I really don't see a lawsuit going that far.

I wonder if the issue had anything to do with the GPL incompatibility with the CDDL license ZFS fell under. This is what keeps it out of Linux as well, at least at the kernel level.