Despite its critics, knowledge management (KM) has not been over-promised; rather, vendors have under-delivered. Blogs can address the gap between KM promise and requirements by letting local expertise emerge. Heres a good background on blogs and how Lucent is using them in KM.
Updated 2004-04-15: Oops, the guidelines were not actually from AMA. Instead, they were response to AMA's instructions on the matter. Time to remember how to RTFA. ;-)