Fundraising drives don't raise questions about the impartiality of the content in the same way that ads might. However, even NPR has sponsors these days (but not ads per se). I think it'd be interesting to hear whether Wikipedia has considered that approach.
I don't know about that. My local PBS station experiences a lycanthropy where they degrade into infomercials for older people every pledge week. They very well know the kinds of programs that pull in more funds.
If the Wikimedia Foundation at any point decides to use their "business sense" and look at the articles that raise the most funds, well... there are questions that will be raised.
