On FreeNAS.org the 3rd beta version of the upcoming FreeNAS version 8.3.0 has already been released, which brings a new ZFS version as an essential innovation. The update to the new filesystem version is optional and has to be done manually; once done, ZFS does not work with older FreeNAS or FreeBSD versions, so the upgrade is a one-way street and needs to be considered carefully. The plugins like minidlna are also available in an updated version - minidlna in version 1.0.24, firefly in version 1696 and transmission in version 2.61. The plugin jail has also been updated in beta 3.
Since software like FreeNAS is most likely to be used on a system that contains important data, updating to a beta version is not recommended - unless you have a complete additional backup. Especially changes to the file system can lead to data loss. FreeNAS 8.3.0 is again more evolution than revolution: features introduced with 8.2.0 like the plugins are improved and continued, furthermore the ZFS file system is updated to a current version. However, there are no real disadvantages to waiting for the final version.