2007.0 stages should contain 2 additional, useful, small packages in world set: app-portage/gentoolkit app-portage/portage-utils For example app-portage/gentoolkit contains useful script revdep-rebuild which can use qfile from app-portage/portage-utils. (/etc/portage/postsync.d/q-reinitialize should be +x.) Adding these small packages enlarges sizes of stage files by only ~0,25 MB.
The stage3 tarballs contain only the packages that are in the "system" target. Neither of these packages are required to have a functioning Gentoo system.