I have not looked deep into this, but you might try Arch Linux ARM [1], which might have newer versions of packages (if it is anything like its x86 variant). It used to be offered on the official Rpi distro page [2] but I think it has since been removed, though I am unsure if that indicates that less effort is going into maintaining it. Regardless, I too would be very interested in scrutinizing these Raspbian security patches to see how quickly they are built and distributed compared with their release date, and if an alternative build of Raspbian that focuses on this was to be released, I would be very interested.