Can Google's Wikipedia Extract Profit from a Non-Profit?

The New York Times (and others) are reporting that Google is working on it's own Wikipedia-like website called Knol (short for knowledge). The site is accessible by invitation only (for now) and differs from Wikipedia in that a) it allows advertising and b) article entries are created and controlled by a single individual. The presumed result is that there will be competing definitions for things like, "Rotary Wankel Engine", let the best one win.

It's an intriguing idea. Wikipedia obviously draws lots of traffic which presents tantalizing revenue opportunities. At the same time, the contributors would likely object to Wikipedia earning millions of dollars off of their volunteer labor. What Google is essentially trying to do is 'privatize' the Wikipedia idea and make it into a business. This raises the question of why hasn't Wikipedia 'privatize' itself. If they were sitting on an untapped gold-mine, don't you think they would? I suspect Wikipedia understands its user base quite well and, for reasons that Google might soon discover, 'privitising' the Wikipedia idea might not be as easy as it sounds.

My second observation is that while I'm all in favor of competition (generally speaking), I don't immediately see the value of dueling encyclopedia entries. Assume for a minute that you're wanting to know what exactly a 'Rotary Wankel Engine' is. You look it up and find 6 different definitions which to varying degrees contradict each other. Do you assume the highest rated definition is correct? Do you pick-and-choose the information you believe? Do you finally finally break down and start fact-checking? That sounds like a lot of work. I'd probably just go to Wikipedia and use whatever they have.