I still don't understand why we should reject the copyleft philosophy and change to an attribution license. I think that our mission is not only to provide free information and knowledge, but also to be sure that it will be kept free. I don't think that we should change our licensing policies in order to be published on Google Knol: why we should do it? If Knols wants to allow its users to publish Wikipedia-derivative content they should change their terms, IMHO.
Massimiliano