MongoDB 2.6.5 is available since 7th of October. Reproducible: Always
I was able to install version 2.6.5 using renamed ebuild from 2.6.4 with default USE flags.
Indeed Mike, thanks a lot. It's in tree. +*mongodb-2.6.5 (13 Oct 2014) + + 13 Oct 2014; Ultrabug <ultrabug@gentoo.org> -mongodb-2.6.3.ebuild, + +mongodb-2.6.5.ebuild: + version bump fix #525176 +