This functionality (especially certified FIPS 140-1 or FIPS 140-2) would be nice to see in UNIX variants. MacOS's keychain functionality is similar, but stores at the application level, and is not FIPS compliant. An implementation of the protected store functionality will allow applications like Firefox, Thunderbird and gpg to have one common place to obtain private keys and certificates rather than maintaining their own individual keystores. An additional application for this would be the ability to use hardware PKCS #11 tokens.
I am wondering why this functionality does not exist at the OS level in most OSes except Windows. A number of applications on many platforms have this functionality, but its at the app level, with their own keystores, and not a standard at the OS level.