Google has just announced Knol (as in a unit of knowledge) that will encourage people who are knowledgeable about a particular subject to write an authoritative article about it. It seems Google wants knols to replace the Wikipedia results that typically grab the first few results on simple searches:
A knol on a particular topic is meant to be the first thing someone who searches for this topic for the first time will want to read. The goal is for knols to cover all topics, from scientific concepts, to medical information, from geographical and historical, to entertainment, from product information, to how-to-fix-it instructions. Google will not serve as an editor in any way, and will not bless any content. All editorial responsibilities and control will rest with the authors. We hope that knols will include the opinions and points of view of the authors who will put their reputation on the line. Anyone will be free to write. For many topics, there will likely be competing knols on the same subject. Competition of ideas is a good thing.
In another apparent attack on Wikipedia — or at least the collaborative model it is based on — Google puts the focus squarely on singular authors of knols:
The key idea behind the knol project is to highlight authors. Books have authors’ names right on the cover, news articles have bylines, scientific articles always have authors — but somehow the web evolved without a strong standard to keep authors names highlighted. We believe that knowing who wrote what will significantly help users make better use of web content.
While it seems odd for Google to go against a collaborative model for knowledge creation — especially since they depend on the masses to help determine which pages are important — my guess is the single-author model helps Google implement the main thing Wikipedia has so far avoided: advertising. If an author chooses to include ads on her knol article, Google will provide her with substantial revenue share from the proceeds of those ads. A collaborative model won’t allow for revenue sharing on ads.
Knol is not without its collaborative elements, however, as Google plans to include the usual collection of Web 2.0 social tools on each knol page, including spaces for comments, questions, ratings, reviews, edits, additional content, and so on.
This is still very beta (more like alpha, I suppose), but one issue that isn’t addressed in Google’s announcement are the licensing options. The sample page does show the content released under a Creative Commons license, so that is hopeful.
It will be interesting to see how this plays out.
UPDATE: Eszter Hargittai provides good commentary here.
UPDATE 2: John Battelle has a quick reply from Jimbo Wales, co-founder of Wikipedia:
[Wales’s comment] Sounds more like Yahoo Answers than Wikipedia to me. It is not a collaborative tool, it is a competitive tool.
[From Google’s announcement] “We hope that knols will include the opinions and points of view of the authors who will put their reputation on the line. Anyone will be free to write. For many topics, there will likely be competing knols on the same subject. Competition of ideas is a good thing.”
[Wales] Very different from a wiki, and not likely to generate much of quality.
Then I [Battelle] asked if he was surprised that Google did it. “I am surprised it took them so long. :)” was his response.
MichaelZimmer.org 
I agree with Umair Haque’s analysis.