Summary about covers it, except for a little detail: http://cgit.freedesktop.org/xorg/lib/libX11/diff/?id=7c996f78914c77fe17e9f4feede980d895d9df51 This little old commit should be added to libX11, together with this xproto this should silence those annoying warnings of: line 136 of inet expected keysym, got XF86MonBrightnessUp: line 137 and other related.
renaming previous ebuild worked fine, i got no obvious troubles when using it...
7.0.12 has been in the tree since March, forgot to close this bug.