Essxjay, it's a pretty deep point and one that we debate at great length at Internet Engineering Symposia. If you protect your hosts, you don't need firewalls. And while firewalls are good at blocking unwanted traffic, they often block useful traffic as well. Newer applications that expect a free open internet are being stifled by firewalls and NAT (Network Address Translation), and if you stifle applications, you stifle the growth of the Internet.

I can go into much more detail, but not here. If you make it down for the So Cal PIPP we can discuss further.