We've been hearing for years from some quarters that the perimeter is dead, we've entered an era of networks without borders, and firewalls are obsolete. We should be focusing our security measures at the data level, rather than the entry point to the network. That's pretty much the stance taken by Asaf Cidon in this article:
Jody Brazil disagrees. He says organizations that can't maintain rigid firewall enforcement are more likely to be compromised, and that firewalls still sustain the foundation of sound security:
On which side of the fence (or should I say on which side of the firewall?) do you fall?