This sounds very, very bad for the modding community. (pasted from Marco's link above)
"nachocheese" quoted Relic's response to his email:
response to my email:
The point of us signing our archives is to ensure that no one can modify them. Giving the community a way to sign archives would be akin to distributing our private keys; it would completely defeat the purpose. It would not make sense for the community to sign archives with their own private keys, as they would have to provide the public key, and any method of doing so that does not go directly through us could be circumvented (this would limit their ability to develop and distribute mods).
Any additional mods we decide to permit will be distributable by the Steam Workshop and bundled up into a single unsigned archive created by Archive.exe. It is possible that a dependency system might be introduced whereby mods can depend on other mods.
Internally, we have not decided to enable the loading of unsigned archives in -dev mod as this could easily be used to “steal” DLC, and would permit user content that conflicts with types of DLC we wish to make.
The direct answer is that we haven’t added the ability to create any mods other than multiplayer scenarios at this time, but are exploring which types of mods we will permit in the future. Any future mods will follow a similar pattern to the scenario packs (a single archive distributed via Steam Workshop), and not that of past CoH mods (-mod <module>).
Relic needs to support modders as they obviously grow the overall interest in the game. Shutting them down would be a horribly shortsighted mistake.