The bug you just tried to hijack is related to the Anaconda installer, and kickstart files used for it. Not livecd-tools or livecd-creator. livecd-creator is tied heavily to Ext3 currently, and unless you are willing to write patches currently there is no quick fix to use BTRFS on the LiveCD, LiveCD is SquashFS anyways, the only part which is added which has a usable filesystem is the COW Ext3 in an overlay file which is created when using livecd-iso-to-disk
Anaconda and livecd-creator or two different things.
Hmm, then I don't understand how guys in the mentioned bugzilla entry got it working? Are they even talking about livecd btrfs in this bug - https://bugzilla.redhat.com/show_bug.cgi?id=571910 ?
If there is a quick fix for this, please tell me what I can do and how to edit imgcreate/fs.py so that btrfs livecd image creation works. I'm really eaget to try btrfs via livecd image.