To the best of my knowledge, posting your creation up to the internet doesn't constitute waiving your IP to what's called public domain.
http://en.wikipedia.org/wiki/Public_domain
Here clearly states
"Any work (of certain, enumerated types) receives copyright as soon as it is fixed in a tangible medium."
If you want to claim some work has entered into public domain, it should either be an IP that's waived/disowned by it's owner, or that it is no longer copyrightable (mostly due to expiration of the copyright protected period). Thus if Disney didn't extend the copyright on mickey mouse and other characters created long ago, all would be able to use those disney characters as the IP leaves the "private domain - where the owner can own the IP privately to the exclusion of others" to "public domain - where no one can claim exclusive ownership and exclude other people to own it"
Thus, it's a misconception to think anything that are released to the internet are in "public domain". Making your work available to the public, be it through paper, CD or internet, doesn't automatically make destroy your ownership of the IP of your creation. Rather, it serves as an evidence that you have created your work and you can use the release date as evidence of earlier creation to claim infringement of your IP when you think someone else has infringed your IP.
No software companies loss their IP by releasing patches through internet. And unless contrary evidence are presented, the best argument should be that the IP of derivative works are owned by the original owners and they allow other users/modders to use those works under the restriction agreements. And try to carbon copy NY Times's web page and print it out for sale, and you'll get sued immediately.
EM has been correctly focusing on this point and stating again and again, many works in this and the previous warhammer fantasy mod are original creations of the people here. The work for bug-clearing, balancing stats, and choosing/begging for various art and units to be included are IP and should be considered as original creations that are owned by this fantastic team.
Other people may borrow the artworks and units from this forum as mtrn and EM did for the creation for this mod, but the .biq file that this team worked out and maintained are clearly hardship that deserves respect and recognition.
Thus, use this 2.5/2.51 mod under the terms set up by this team of owners.
No no for releasing derivative works of this mod.
[Edit: Internet is considered as a tangible medium as it can be perceived by our senses. As contrasted to intangilbe medium like "idea in my brain" that cannot be sensed by other parties until they are fixed on tangible medium - like paper or internet]
