It'd be nice to have comps-enabled repodata on the install media (at least the DVD, perhaps also CD's) so one could use it or the mounted ISO as the "base" component in yum as-is, instead of having to stick with an online one or to generate the repodata locally.
Having it on the DVD sounds doable. The binary CDs are chock full of wonderful goodies, leaving no room for repodata just now.
*** This bug has been marked as a duplicate of 139077 ***