Just a quick clarification on collection copyrights: if you put together a collection of materials, then you acquire a copyright in your particular presentation of the collection, not in the materials of the collection themselves.
This means that Bomis' collection copyright would be violated if somebody were to copy the website wholesale. If on the other hand the wiki sources of the articles are downloaded one by one, and a new web site created out of those, then Bomis' collection copyright won't be violated. If this new web site doesn't offer the articles under GFDL, then the individual article authors could sue of course.
This is similar to a Linux distribution. If you create a distribution, you can claim collection copyright, and somebody who copies the CDROM image without permission is in violation. Everybody can however create their own distribution out of the exact same free software components that you used, without violating your collection copyright.
Axel