Just reading this article several months later. I think Lanier's viewpoint is definitely conservative, but I don't think he should be dismissed as a luddite. The problem, from his point of view, is that the collectivist nature of Wikipedia has the potential to frame an individual's contributions and arguments as not only incorrect but morally wrong because they go against the grain of popularly held beliefs. On the other hand, the assumptions on which a collective bases its reading of an issue might avoid the same scrutiny if the editors of Wikipedia collectively do not believe a statement to be controversial. Not every statement in any Wikipedia entry is referenced or cited (it might make for terrible reading if it were) but surely there are underlying assumptions throughout Wikipedia articles, even ones that are copiously cited.
Lanier's concerns are legitimate and should not be dismissed just because they are cautionary and conservative. Wikipedia is here to stay, and it is a useful tool. However, there is a danger that a novice to a subject might read an article to get the wrong idea about it, not just because someone has populated the article with incorrect information, but because the article contains many underlying assumptions that are not overtly questioned. This danger is not exclusive to Wikipedia as a resource; but while Wikipedia offers a greater potential for collaboration, there is also the potential for a dissenting voice to be shouted down by a collective that is unwilling to take a chance on an expert opinion.