for Mac Pro 2,2 owners
Due to many Macs being stuck on Mac OS 10.7 (or even 10.6 or earlier), without going the hackintosh route, the solution to continue to receive security updates is simply to boot into Linux, FreeBSD or even Windows 7. Basically every other modern OS is going to support your Mac long after Apple. Apple it seems is even having problems keeping its latest greatest shiny up to date security wise. Have no fear about the one thing Apple will continue to keep to date with ever more bloat is iTunes.