Since /etc/localtime is a symlink now from which the chosen timezone can easily be determined via readlink() the file /etc/sysconfig/clock is now obsolete. If anaconda still writes that file, please just drop support for it. if not, please close this bug right-away! Thanks! (if anaconda uses timedated for writing this file, /etc/sysconfig/clock is not written anymore anyway, and this bug report is without value).
This bug looks to have been fixed for many anaconda builds now but missed being closed. If you find you are still experiencing it with Fedora 18 Beta (RC1) or later, please re-open the bug.