Let me check the release notes,
even with the latest 12.1.5, WE 2008 is supported, you need to wait till 12.1.6 or higher, will get to know only after its released.
http://www.symantec.com/business/support/index?page=content&id=TECH224712
subscribe to this news letter
https://www-secure.symantec.com/connect/forums/email-notification-about-symantec-product-updates