In this link:
http://www.anandtech.com/show/5433/microsofts-refs-filesystem-for-windows-8-server-explained
you can see ReFs is very similar to B(e)Fs that is it uses tables to memorize directories, files and metadata as B(e)Fs doess unsing a database.
There a lot of differencies too, as the Storage Spaces and the anti-corruption techniques, but in the end this thing could (maybe SHALL) be added to B(e)Fs, too.
Let’s consider this post as a think-thank for an ipothetic BFS 2, right?
fano