Stock are hot because folks say they are and stock price bears about as much relationship to economic performance as Mike Tyson does to Billy Graham. Some if this is obscured by rhetoric about community or community-building features. Lycos crows about its community of members. Oh, well, I guess it must be chat rooms, or personalized news. Nonsense, horsefeathers, balderdash.
Communities form when human beings have frequent, mutually-beneficial interaction.
Or the community of any other portal, for that matter. No, probably not. There are some things we can point to that define what knowledge management might be. Make up your own definition. Pretty much everyone else is.