If you don't impact the business process with Enterprise 2.0 you won't unlock value.
If you introduce a new tool, you can't make them use it. Tools should fit in their daily routine. If not, users will easily reject it.
There were differences about using force to get people to adopt Enterprise 2.0 tooling. Most said, Don't use force, make it voluntary. But it does depend on the type of e2.0 project. For instance, an example was given about social project management. In this case you agree to do project management in this way. But with communities using (a bit of) force is restrictive.
Helping people use e2.0 tools and integrating them in their work processes requires patience and lots of training. Sometimes you even have to start by explaining what a webbrowser is. Focus on the e2.0 concepts not on the tools. Most people understand the concepts better than the tools... Enterprise 2.0 projects almost always start as push, not pull. Start by solving daily problems. Because most people don't ask for e2.0 concepts and tools.
Context is a key word in this area. Linking people (expertise), information, processes and tools. Formal processes, information need context to understand them.
We also see a role for e2.0 in the definition of new formal processes and improve them continuously. Basically most of us are unconsciously looking for improvements to business processes.
Social tools and formal business tools are not or hardly integrated. (At least we don't have examples... We do see vendors moving into that space, like SAP.) People are not middleware. Extra tools are see as a barrier for knowledge workers. E.g. they live in their email. Every extra tool for sharing, storing, etc is seen as a hassle.
Also see Emanuelle Quintarelli's notes here.