I remember seeing an article here these past few weeks talking about the business model of Wikipedia and how it's supposedly inherently flawed. Wikipedia doesn't bring in a lot of cash, but it rather sets a sad tone for itself how unfortunate that may seem.
Personally I'd be more interested in seeing StackOverflow branch out. What have they done these past few years? It seems like StackOverflow has remained stagnant, yet they have so much potential.