From the OSX Server mailing list:
<p>Don Brady, former senior Apple engineer has started a company to bring what appears to be a commercially supported version of ZFS to OS X.<p>Ten's Complement: http://info.tenscomplement.com/<p>Details are sparse, but they have a twitter feed and email newsletter. When I signed up I got a invitation to join the beta program.<p>From his twitter (http://twitter.com/tenscomplement)<p>http://lists.apple.com/archives/macos-x-server/2011/Mar/msg00194.html