Dedupe is being talked about as far as I know and is a goal of the project,
and it has optimized mode for working with SSD. So on and so forth.
Btrfs is still about a year away, I figure. And when you make a major change
to a project, like going from FreeBSD to Debian for CoreNAS stuff, it's
going to take at a minimum several months to create a working product and
that is why I figure that it's likely that by the time CoreNAS is out the
door Btrfs will be in a usable state.