I think the main problem with the case for “E2.0 inside the firewall” is the word “firewall”, which represents an outdated but still common attitude towards maintaining organizational boundaries. I wouldn’t be at all surprised if an organization that relies on firewalls struggles to get the benefits from open distributed business and technology, including Enterprise 2.0.
"It’s true that many forward-thinking organizations are becoming more transparent, and the borders between them are becoming less distinct. Still, eliminating the firewall altogether would require a lot of infrastructure changes. ... An even bigger challenge is the political one. Changing the Internet from a 'network of networks' paradigm to a 'unified network' approach would require far more coordination than most companies — and countries — would be willing to undertake."I agree that shifting away from firewall-based security is a significant strategic move for an organization, not just infrastructure but also political. There are some political issues that would have to be tackled, if the organization is to achieve any potential benefits from Enterprise 2.0.
But the shift away from firewall (sometimes called Deperimeterization) doesn't necessarily entail the second shift Dean mentions, from a 'network of networks' paradigm to a 'unified network' approach, and I am not advocating this. There will perhaps always be limits to interoperability, and there will always be some structure to the network of networks, but this structure will be more open and innovative, and not driven primarily by an obsolete security architecture.