Is Knol a Threat to Wikipedia?

Much as I appreciate Lyn’s excitement for another Google offering, I’m not completely sold on the concept of Knol yet, for a few reasons:

Knol

I know there are issues with Wikipedia and their collaborative approach, but I think that over time it tends to balance out fairly evenly, so that Wikipedia’s error rate is about the same as that of the Encyclopedia Britannica (see here).
I don’t see how Knol improves upon the Wikipedia in that regard, in fact it seems to me that you will end up with hundreds of conflicting articles on subjects each claiming to be the truth.

Secondly, allowing people to run AdSense ads on there will encourage a lot of spamming. The editorial process, and nature of Wikipedia, means that articles tend to be written by people who are simply very interested in a subject, rather than those who are looking to make some easy AdSense money. I predict a wave of ‘informational’ pages from places like India on the usual topics of spammers – casinos, and the like. Early evidence is backing this up – there are currently more results for ‘viagra’ on Knol than for ‘New York city’!
(also check the comments on most articles – a lot of spambot activity! “interesting article! Visit my blog www.something.com”)

Finally, the fact that it is a Google product doesn’t guarantee success. I doubt that they would, but if Google allowed Knol pages to rank higher simply because they are part of Knol, it would clutter the natural search results with junk. Then people will simply turn to Yahoo, MSN, or some new start-up that has better search results (Cuil.com perhaps?). There is nothing intrinsically unique about Google’s search that could prevent it from going the way of HotBot, AltaVista, Excite and many others if they don’t deliver what people are looking for.
And, yes, having the backing of the world’s #1 brand gives Knol a head-start that it wouldn’t otherwise have, but so did (does?) Friendster, and how many people do you know use that?

Maybe I’m completely wrong about this, I’m sure there must be a few people at Google smarter than me who have already thought of these points, but I’m going to reserve judgment before declaring Wikipedia dead and buried.