There is a good article on TECHNET on Next Generation Firewall (NGF) and the fact that most, if not all, companies accept port 80 in/out meaning traditional F/W are less and less effective against malware using this port as a mean to call home or come in.

The Article nicely summerize the need to look for more than IP/PORT/PROTOCOL but also for the type of Payload going through.

Although not a new technology, the evolution of Malware is a growing issue which makes that technology more and more relevant.