I will expand on one of Aaron Meyerowitz's remarks.

I am somewhat possessive about what I have written. Indeed one of the hurdles I had to overcome to participate on MathOverflow was to accept that what I submitted could be changed by many other people. I was upset when it happened, and the major thing that kept me from voicing that upset was the FAQ, which said other people could do that. However, most of the edits were sensitive to the thrust of the post, and turned out to be more changes to style than serious changes to content. I have grown to be more comfortable with posting answers on this forum, as my input has mainly been given due respect.

If I were a contributing author to Wikipedia, I would have to overcome a similar hurdle, especially as there would be no consensus as to what is "the" information to present. The posting would not be "mine" anymore.

If Wikipedia had a mechanism for including outside references in a useful fashion, I might be more inclined to offer material for its use. My impression of the current system is that there is a "References" section in the article which includes hyperlinks to other material. My suggestion would be to enhance this so that the link expands into essentially two documents: my version of the article, which I agree to allow Wikipedia to keep a local unedited copy and display repeatedly for their benefit, and a meta document which I agree can be modified in tandem by me and Wikipedia editors whose main purpose is to explain discrepancies, notation changes, and other elements of context to allow the reader to transition between the Wikipedia intro and my version. Wikipedia could then use (or not) my version of the article, the content of which I have control, while maintaing editorial control over their version. Even if I decided that my version was no longer appropriate, I could only petition for its removal, as I had granted Wikipedia the right to use a copy of the unedited version in perpetuity, and I have access to the meta document to say that I think a better version is available elsewhere.

It seems a little more complicated then just providing a hyperlink, but it has the advantage that it could be maintained by Wikipedia, the situation between editor and author is clearly defined and separated further, and the meta document has the flexibility to handle most of the situations that arise. Also, this kind of mechanism would accommodate my sense of possessiveness, and allow me to write things which I could use for my own purposes as well as allow Wikipedia to enhance their collection.

Gerhard "Will Write For Venti Mochas" Paseman, 2013.05.22