Any chance of getting the rtprio pam_limits patch into portage? The current stable ebuild version doesn't have it incorporated upstream yet. There are copies floating around, I installed the one available from: http://gentoo.zugaina.org/gpo/portage/sys-libs/pam/files/pam-0.78-realtime.patch yesterday and it appears to work fine...
To 0.78? No way, it will be removed as soon as 0.99.x is stabilized, no changes going there.
I didn't realize there were short-term plans to stabilize 0.99, I saw that it was masked, sometimes packages spend months to years masked before they're stable...
~September hopefully. :) http://www.gentoo.org/proj/en/base/pam/upgrade-0.99.xml