Yeah I saw that. I was never too excited about a private ZFS port for OS X, because this is the kind of thing that can happen. Still very tragic that the original deal to put ZFS in Leopard and Snow Leopard died.
As with all things Apple lately, we can only wait and hope that the wisps of smoke visible in current products herald a brighter future. In this case, that wisp would be the nascent CoreStorage LVM that appeared in Lion could be the first step toward a modern filesystem for OS X. As great as ZFS is, I'd be content with an Apple-developed LVM-backed copy-on-write facsimile.