Is the personal firewall necessary?
Again on Security Incite, Mike says that there is no need for personal firewalls anymore, as the one provided by the OS seems to be enough for most cases. I agree with him when he says that where it is not enough you'll need it from a bundle of other things, like AV and AntiSpyware. I believe we will start to see products like "endpoint security solution".
The AVs are already doing anti-spyware, the personal firewalls are doing some AV, and so on. In a near future every desktop protection product will do all this stuff, protect against "malware" and external attacks.
Corporate editions will also include NAC/NAP integration. There is no sense on installing dozens of agents to keep bad thing out, just choose a single good one to do all the job. It's also a good market trend for the companies looking for ways to survive, include all security features in a single agent and sell it as "endpoint security agent". Nice.