When emerging recent gentoo-sources with USE=deblob, I get the following message: "gentoo-sources is UNSUPPORTED by Gentoo Security." This is confusing, as gentoo-sources isn't unsupported. Only the deblobbed version is.
Created attachment 229977 [details, diff] Patch for kernel-2.eclass Tentative patch. The wording of the message might be improved, but you get the idea. ;-)
ulm: thanks, merged a patch based on yours now.