FreeBSD foundation have ended long time speculations by a press release issued an hour ago.
We are pleased to announce that FreeBSD will be dropping ZFS in favour of HAMMER2 file system. It is time for us to move to more modern and less resources hungry file system. ZFS has served us well but it is time to retire. As of today 3 full time paid developers will be helping Matt Dillon make necessary kernel changes to accommodate new file system.