HackerGuardian (Comodo) is already sending out the notices to users saying that they'll be out of PCI Compliance in 7 days if they are not updated. I expect to see a rush of users needing that X-Cart PHP 5.3 patch
EDIT NOTE: I mistakenly said HackerSafe (which was bought by ScanAlert which was bought by McAfee). I've edited it to say HackerGuardian (Comodo)