Excellent article.<p>Interesting how these things progress by getting complex, then a simplifying design is found that makes the architecture simpler, or at least with fewer "moving parts".
This article has just been slashdotted:<p><a href="http://hardware.slashdot.org/story/09/08/01/0211232/A-Short-History-of-Btrfs" rel="nofollow">http://hardware.slashdot.org/story/09/08/01/0211232/A-Short-...</a>