Bill writes in his blog Eclectic about KM loosing popularity. It is only logical for it to not be so popular, because of the complexities and fuzziness of KM theory around it. Albeit if there is one. The tools might get popular, but still does not mean they are a good solution (especially when the problem is not wee defined).
The danger is on people buying tools again, thinking that by doing so, they bought the solution to KM, which is never the case. I argue and will always, that tools do not give you the solution , it is illogical and it does not make sense. If you want to be successful, you must follow the PSST system, where you define clearly the Problem, Make sure is not just a Simptom, and then think the Solution through and through ON PAPER. Normally this translates into screen views of what you want to see. THEN , and only then, you look at the tools that will help you build YOUR solution.
Leonardo.