2009/2/2 Sam Johnston samj@samj.net:
Exactly. There is nothing 'customary' about massively collaborative development of works.
Just about every film of any significance. TV series. Computer games. Heh just about every bit of major software. Maps of large areas can rack up very large numbers (depending on a couple of factors).
The other thing to remember is most wikipedia articles don't actually have that many authors. en has a mean of 17.83 edits per page. Allowing for bot edits (which mostly don't qualify for copyright), distortion of that figure due a few very large articles histories and people editing more than once and you are pretty close to what some scientific papers rack up in terms of authors.
Most things you could use content for already have customary methods of giving attribution. That isn't going to change.