Stephen Danelutti has created an Enterprise 2.0 meme map, capturing the ideas associated with the marriage of Web 2.0 and the enterprise.
It's a good place to get the discussion started on the obvious trends impacting business models, the workplace, customer engagement and technology. Turning the discussion into a day-to-day, steady embrace of enterprise 2.0 concepts and strategic initiatives that cascade through an organization is the challenge.
What's a likely sweet spot for applying Enterprise 2.0 inside the firewall? Keeping adoption of your preferred tools simple within the complex landscape of your organization so users won't prefer theirs; flatten your network as much as you can, open your systems using simple, open standards, and push the tools out fast (the network effect is pronounced with these tools so speed does matter). Make Enterprise 2.0 as simple as humanely possible for your organization in this framework, but no simpler.
Check out Dion's ten predictions for Enterprise 2.0 in 2007
See also Andrew McAfee's writings
More on Enterprise 2.0 here