Vendor Supported Virus Updates

I would like to find out the industry trend regarding virus updates and vendor responsibility. I need opinions from other IT professionals on this subject. The situation that has occurred with all of the new virus?s that are plaguing us lately is that some of my clients have been concerned with virus updates. My belief is that when a vendor sells a solution, it is the responsibility of the client to update there severs with the latest virus software updates. Please give me feedback on this subject.

Thanks,

Jason