There will come alot more of those things... You should also get a decent firewall and set it up proparly (that's the difficult part). Keeps most of the worms outside (or inside). Also look at the logs sometimes :s.
Especially when you use kazaa like programms it's usefull to keep your AV things up to date anyways. There are thousenths of virusses on kazaa if not millions. If I'd care about every new virus I'd be buisy all day updating my AV database and never get done in the next 10 years for sure.