I heard that Joel Spolsky recently said Stack Overflow has more monthly active users than Wikipedia. Is that true? What are the trends? What about other Stack Exchange sites and all SE combined?
The comparison was on a seemingly reasonably number, that is users who made at least five contributions in a month. See Edit activity levels of registered users for all Wikimedia projects: about 75k active editors per month, or over 200k considering any activity, or 12k with power users only. All excluding unregistered users.
At How many users does Stack Overflow actually have? there is some information on the total number of accounts and I read some interesting analysis on Server Fault, but not much on 5+ active users/active editors/active contributors/active posters or however you may prefer to call them.
At Wikimedia all edits to articles are equal (actually, edits to pages in content namespaces), but what's the equivalent of the community-accepted version in the main namespace here? Questions and the most upvoted answer to them in non-meta sites? What about comments and edits?