Fedora has supported Btrfs as an install-time option for many releases now, but it hasn't been made the default. Generally the idea gets canned every cycle over problems and/or there being no viable fsck utility for the file-system. However, in February of last year, the Btrfs fsck repair tool was made available. While it's been nearly a year that this tool to fix common Btrfs file-system errors has been available, Btrfs hasn't seen any new love in the Fedora land.
There's now a new mailing list thread on the Fedora "devel" list about making Btrfs the standard file-system for Fedora.
Richard Jones of Red Hat was the first responder to this user's thread with saying there's still "a couple of issues with btrfs which I believe absolutely must be fixed before it can become the default." Richard pointed out two bugs in Btrfs dealing with data corruption and poor performance in virtual machines. In a later post, Richard Jones went on to say, "I'm deeply unhappy about data corrupting bugs being effectively ignored by upstream for months. That's not good."
Reported by another Red Hat employee has been other Btrfs bugs, including performance problems and other general issues.
Josef Bacik, a former Red Hat employee working on file-systems who is now working at FusioIO along with Chris Mason on Btrfs, said he's waiting for the major Anaconda installer re-write that took place in Fedora 18 to settle down before he's pursuing Btrfs work in Fedora again.
Other responders to the Fedora Btrfs thread chimed in that they're waiting for Btrfs to be as reliable as the EXT4 file-system.
With there still being reported upstream Btrfs bugs that are yet to be resolved in the latest code (the Linux 3.8 kernel), it's probably unlikely all of these remaining issues will be worked out in time for Fedora 19. At the moment developers are looking at releasing Fedora 19 in May of this year, which would be rather a rather tight time-line for working out the remaining Btrfs problems, seeing that the file-system receives sufficient widespread testing on Fedora Rawhide/19, and convincing the last of the developers holding out on endorsing Btrfs that it's a worthwhile change over EXT4. Fedora 20 looks much more likely for any potential Btrfs migration.