Hello,
Incase of versions SAV 8 and SAV 9;
Symantec Antivirus 8.0 reached its End of Support Life as of November 30, 2005 and Symantec Antivirus 8.1 reached its End of Support Life as of January 31, 2007, as defined in the Symantec Enterprise Technical Support Policy. Therefore virus definition updates are no longer supported for this product.
Symantec Antivirus 9.x will reach its End of Standard Support as of March 31, 2009. Virus definition updates for version 9.x will be discontinued on April 1, 2009. Please contact your account manager or reseller for information about our current shipping versions.
SAV 10 is almost at the End of its Life.
I would say, this is the right Time for you to upgrade to SEP 11 or SEP 12.1 (Which may be Releasing this Year)