Zenwalk has been shipping the Brain Fuck Scheduler since 2010 as its default kernel scheduler beginning with the 6.4 release and they're still relying upon it to this day rather than the Completely Fair Scheduler (CFS) or O(1).
The Brain Fuck Scheduler continues to be maintained by Con Kolivas, but more than three years after it was conceived, it remains out of the mainline Linux kernel just like Reiser4; Kolivas has no ambitions to mainline the work.
Kolivas continues to independently offer the BFS scheduler patches via his web-site. The patches are actively maintained and updated, the latest BFS 425 version was updated just days ago for the Linux 3.6 kernel. Other Linux distributions in bed with this desktop-friendly low-core-count-optimized scheduler include PCLinuxOS and Sabayon Linux.
The BFS-patched kernel for Zenwalk 7.2 is based upon Linux 3.4.8.
Zenwalk 7.2 continues with the distribution's goal of providing one good application per task and fitting everything within a 700MB ISO. With the 7.2 release they also aimed for "100% Slackware Linux compatibility" while keeping most optimizations that were introduced during the last year's of developments.
"In a nutshell : Zenwalk can do everything big desktop distributions do : but faster, easier, in a 1 CD ISO, and in a way you can still understand." The release announcement for Zenwalk 7.2 can be found at Zenwalk.org.
While Zenwalk isn't as popular as Ubuntu, it's a fun distribution to play with from time to time. It also has proper Phoronix Test Suite support so there may be some new comparative benchmarks of the distribution coming up soon.