A local administrator should have means to unmask masked packages in a persistent manner. Editing package.mask file is problematic, because if you rsync the portage tree, the changes will be overwritten. I propose a file /etc/package.unmask or such, the contents of which will have the opposite effect of /usr/portage/profiles/package.mask.
This work may be done along with fixing bug 190.
You can get around this problem by using anoncvs rather than rsync (described at http://lists.gentoo.org/pipermail/gentoo-dev/2002-January/008954.html ). I'm marking this as "WORKSFORME"
Only unmask seems unappropriate, one might also want to mask certain packages so they will not get upgraded automatically when doing a world update
