Just kidding… ;-)
This is a really nice article pointed out by Iban Nieto. The comparison with ZFS is (like agent Smith was used to say): Inevitable.
Reading the article, seems like Linus Torvalds is already using btrfs, and i do remember this mail from him in the GNU/Linux Kernel mailing list:

 ...
 And yes, maybe ZFS is worthwhile enough that 
I'm willing to go to the effort of trying to relicense the kernel
...

Well, using The Matrix quotes again (yes, i really like The Matrix ;-), i could imagine the following conversation:

Bane (AgentSmith): Not impossible. Inevitable. Goodbye, Mr. Anderson.
Neo: You were right Smith. You're always right. It was inevitable.

And obviously, this one too:

AgentSmith: The great and powerful Oracle. We meet at last.
 I suppose you've been expecting me, right? The all-knowing Oracle is never surprised. 
How can she be, she knows everything. But If that's true, then why is she here? 
If she knew I was coming, why didn't she leave? 
[sweeps plate of cookies off table] 

peace