Good post by Nancy Dixon on why we share knowledge. Covers important implications for knowledge management and the roles of people within the enterprise.
My own experience is that I have seen a largely self-selecting group within companies who are very willing to share knowledge widely. It is often the case, though that precisely the people you would like to have additionally participate in knowledge sharing methods like blogs and wikis will not. Using specific job roles like knowledge archivists and business information experts is useful as well. With the emergence of intranets and the shrinking of physical corporate library facilities, the assumption appears to be that searches will replace much of that infrastructure. Knowledge and AI based approaches were widely explored in the 80s, but only partially successful. Years later, well after intranet search became common, I was still being asked for ways to store key knowledge upon company retirements.
Good idea to continue to look at the incentive that can be provided to people to make knowledge readily available and usable.