Description of problem: On the livecd, xfce4-panel should not show the first-run dialog but use the default panel config. I'm afraid the only way to archive this is to provide a full set of config files. Version-Release number of selected component (if applicable): F15 Beta TC1
Fixed in http://git.fedorahosted.org/git/?p=spin-kickstarts.git;a=commit;h=a79a7c6a40e068efc8c187d2588625bebe2d44d8 and should be available in the next nightly and F15 Beta.