No, only after FC5 inclusive. On vanilla FC4 you get
# grep enabled /etc/yum.repos.d/*extras*
/etc/yum.repos.d/fedora-extras-devel.repo:enabled=0
/etc/yum.repos.d/fedora-extras.repo:enabled=1
I don't know who is right, but when googling for it I found several
sites that all say the same as Paul.
James