Great post. I would also like to add another dimension to the discussion. There are really two parts to Web 2.0- the social media portion, which is well covered in previous posts and the Rich Internet Applications (RIA), which is the driving technology behind the Social media portion. Probably over 90% of enterprise IT web applications are still utilizing the Web 1.0 technologies, where users click next, next and submit. A typical enterprise user will go from rich sites like Amazon, Expedia, Facebook, etc. to web apps behind the firewall that require thick training manuals. RIA are web apps that has the performance of a desktop application. Technologies such as AJAX and FLASH that offer rich interactions are still a challenge to most IT shops, which have legacy systems to support. Security is also a challenge since the architecture is different. This requires some investment upfront but RIA implementations can offer quick returns since applications are much more interactive with minimal training. So in general, I think IT has to grapple with the cultural transformation of Web 2.0 as well as the technical integration into their current enterprise architecture.