After the boom, is Wikipedia heading for bust?
newscientist.com
newscientist.com
Also, I wonder if they checked any languages other than English. Some of those may still be in the rapid growth stage.
On the other hand, there is a point at which the low hanging fruit articles have already been written. In areas of science or math, for example, wikipedia's coverage far, far exceeds my own knowledge of the subject. In many cases, I suspect that in many areas there is little besides formatting or editorial fixes that can be added without already having a phd in the subject. And while this is certainly a great thing for the quality and comprehensiveness of the encyclopedia, it doesn't help when you are looking at the number of new pages being written.
/humour
I say google should buy them and profit from ads, millions of them.
Add more eyeballs to their web properties.