These are the ZFS binaries from Mac OS X Snow Leopard, build 10a286. This was the last release before Apple removed it from Snow Leopard. I've been using them on the release build, 10a432, without a problem. I haven't come across any kernel panics yet, but there is still weird behavior if you disconnect an external drive without "zpool export". But the Trash actually works!
User beware, but this seems to be a step up from r119.