This is news because although you don't use the product, there are many people who do. Norton comes preloaded on a lot of machines, and there are plenty of non-power users who just maintain the status quo when they get a new machine. Norton also has significant brand recognition (I think they're one of two brands with major name recognition in this area for the average consumer - McAffe being the other), so there's a certain amount of "Nobody ever got fired for choosing IBM" Syndrome at play.
It's news because it could represent a critical vulnerability to these users. If the source is exposed and properly analyzed by sufficiently intelligent, yet malicious people, they could launch a zero-day on the antivirus software itself, leaving a system unprotected, and possibly silently unprotected. That's bad.
