I think we all agree that the best way to deal with such accusations is to write comprehensive, neutral, well-sourced articles. Incidentally, that is also what someone like Neal Horsley should be most afraid of. So, what he is doing is very stupid, but then again, he is a stupid man.
Of course Wikimedia will face lawsuits. Our question should never be if a battle is worth fighting, but only if the article that someone complains about is sound from a legal and policy point of view. If it is, finding the money to pay for legal expenses is not going to be the problem. We'll just have to ask.
Erik