Freenas 8.2 is currently in a second beta version and is expected to be released in May. Besides the change to FreeBSD 8.2 as the base, a major change is the support of plugins, so that various software (including minidlna for media support). An upgrade from an existing Freenas 8.0.4 installation should be possible without any problems, the use of the beta version on a productive machine with data is not recommended.
I have already had a look at the new system. Plugins are distributed as PBI files, but first you have to activate the plugin system. There is an instruction for this in the Freenas-Wiki, so I won't repeat this here. Currently there are only three plugins: minidlna (for DLNA support), transmission (as a bittorrent client) and firefly as iTunes server (even if the versions seem to be no longer being developed).
I first tried to set up transmission - but apparently there are still problems in general, at least in my test installation (realized via VirtualBox 4.1.10) it didn't work (no access to transmission), which may be due to the installation itself. You will have to see this on a live system - but especially on a NAS you should not play around with the operating system if you like the data 😉