livecd-creator previously added 'liveimg' and used root=CDLABEL=;
it's easy enough to support that old syntax for now at least
and it will make it easier to get people testing
Fedora/Red Hat live images are implemented as an ext3fs inside of
a squashfs. Writability is achieved with a device-mapper snapshot
on top of that.
This gives the basic support without a lot of things like persistent
overlays, iso md5sum checking, etc and also with a new basic syntax
that has to be specified as root=live:LABEL=...
Harald Hoyer