The full announcement can be found here on the OpenZFS project website:
For developers and users of FreeBSD, the formation of OpenZFS clarifies the future of ZFS support for our platform. The FreeBSD project is now an equal partner in defining the course for ZFS. OpenZFS combines the man power of the FreeBSD, Illumos, Linux, and MacOS communities to provide a level of test coverage, feature development, documenation, and support that wasn’t possible with our separate efforts. Most importantly, OpenZFS will improve platform interoperability and reduce fragmentation of ZFS implementations.
Today is an exciting day for ZFS and the FreeBSD platform. I encourage you to browse http://www.open-zfs.org and to get involved. You are officially invited to help make the future of OpenZFS!
Justin T. Gibbs
The FreeBSD Foundation