I kinda just agree with susikala. Esp after the fsck.btrfs announce, seems like just drama.
XFS is great for some things (that overlap with what btrfs hopefully will be even better at _in the future_). For now I am psyched about XFS improvements -- which is what I thought the talk was about. Why? Because XFS is infinity more reliable right now, and I use it. It would not be news to say that the ext4 has shortcomings and btrfs is still in serious development.
In essence what I am saying is that at least the only thing that Mason or Chinner have killed is ext4. ;-P hey where is reiser4 anyway ;-P