My opinion so far about every Google initiative is that they do it better than most and almost always accompanied with a sizeable business strategy to backup the product.
Latest in their offerings is their version of wikipedia: Knol is different because it credits and pays the authors and by the same token makes them accountable too thereby offering at least a bit more realiability than free-form authoring ~Smile~. I am very interested in seeing how the accountability comes into play.
Accuracy of information in rare but conspicuous cases proved to be a pain point with Wikipedia however the 'model-shift' towards accountability in Knol and its acceptability would be interesting and only remains to be seen once it comes live. Such a model could have its own pros and cons because from the looks of it the Google plans to balance the ownership factor with the ratings applied and this implies a lot of user feedback, again something that can only be successful with time and adequate user participation.
For more information about Knol, please click here.