Yeah I call them Google-Killers. Google Product killing affiliate marketing. Orkut killing myspace/facebook. Google Analytics killing quite a bit of web analytic companies out there. Google Phone soon to kill cell phone providers, etc., etc.,
I think this KNOL idea seems to be good and since google control the net more or less it should also be a sucess.
For fun I just setup http://www.ontheknol.com to track Google Knol frontpage articles, similar to how other sites track Wikipedia. Now I just need to finish up the automation aspect of it, so I can pull in the latest information daily.