I am a consultant and coach in the fields of knowledge management, knowledge work and learning organizations.
We seperated the knowledge managmement domain into four subtopics: knowledge strategy, knowledge transfer, knowledge creation (aka innovation) and knowledge infrastructures. In the field of knowledge infrastructures besides architecture and office design (physical infrastructure) the virtual infrastructure plays an importal role in globally distributed organizations. We used intranets, portals and ECMS-systems ten years ago. Nowadays we use wikis, weblogs and social networks on top.
For me Enterprise 2.0 is close to the combination of McAfees definition 1 and 2: Enterprise 2.0 is the use of social software in companies, or between companies and their partners and customers in pursuit of the companies goals.
Many enterprise 2.0 applications have values embedded that we need to survive as an organization in the knowledge society and knowledge economy. Examples of that values are openness, transparency and participation.
Organizations often are inert systems. People in powerful positions fear values like the ones mentioned above and are not willing to drive the necessary changes.
Working = Learning, 2.0, Knowledge Era
Video: http://enterprise20blog.com/2013/09/02/soziale-technologien-als-treiber-fur-eine-renaissance-der-wissensmanagement-praxis (in German)
Report: https://de.slideshare.net/cogneon/benchlearning-berichtsocialintranet2012 (in German)