If you have anything about him being full of BS, I'd sure like to read it.
He was a bit confused at first, then to save face he's changed his argument a bit but hasn't let go one bit of the gloom and doom fear part of his argument.
The real problem is users will do stupid things and install trojans viruses and not buy any anti-virus protection. The problem this guy is talking about has been around ever since NT. However, with every new OS everyone wants to find the silver bullet that will get their name in lights. He thought he found it, but all he really found was that if you connect machines to the Internet and run trojan horse programs you can cause problems.
But let's take his scenario out. Let's say every machine in the world is running XP. And there are 5 bad users that run the trojan that will exploit the ports. Now let's say all the other machines in the world that are running XP have their firewall on...guess what nothing happens to those machines that are protected.
Bottomline: Install a good AV program and run a firewall. I'm using a dlink 713P and I'm pretty much hidden from the world.