There shouldn't really be any urgency... (Score 1)

.... If your firewall, anti-virus, office security etc are all taken care of properly. Protect the network then think about individual servers/pc's. A friend of mine works for a large law firm in London that got screwed by Blaster, his network security was spot on until he looked at all those bogged down home user vpn connections with no Personal firewall. Leave no stone unturned on the network and you should be ok.