BobbyDigital said:

If the rule is you should have the blu-rays before downloading the despecialized editions so that you aren't technically getting something for nothing, then why aren't you supposed to own all the different versions of the movies that were used as sources for the despecialized versions? If you only own the blu-rays, then it could be argued that you're profiting from the piracy of all the releases that aren't blu-rays.

You might benefit from a read of "What colour are your bits?": http://ansuz.sooke.bc.ca/entry/23 I misread your post. Sorry.

I doubt that the copyright holder in this case would care that this is a multi-source derivative work. Any case against this would be cut-and-dry enough.