openal-20051024 doesn't break backwards compability as much as it is said to. AFAIK all that must be done right now to make it backwards-compabitable is to force all programs using old openal to link to alut as well.
Created attachment 78291 [details] blender-2.41.ebuild [modified] A modified ebuild that compiles with openal-20051024 and alut-20051024
modifying /usr/lib/pkgconfig/openal.pc to export -lopenal -lalut instead of -lopenal might work as well for anything that uses pkg-config (blender does not... shame on it)
sorry, didn't notice this thing set itself to resolved
Please, attach a unified diff, not the whole ebuild...