Fedora sevens xfce4 package is a steaming pile of incompleteness.
Here are very rough steps to getting xfburn going.
do the ./configure && make && make install on the above libs
svn co http://svn.xfce.org/svn/xfce/xfburn/trunk xfburn
# the pkg_config_path is needed so xfburn can find the pkg-config file for libburn-1
# you need to add /usr/local/lib so that xfburn can find the libburn … libisofs libs.
create a file /etc/ld.so.conf.d/libburn.conf and add the the following content
# then run
sudo /sbin/ldconfig -v