In World In Conflict's latest Q&A, the developers hint at things to come.
Q: Will there be an 'Army Creator' feature where you can create your own faction with your own units in-game, define bonuses etc?
So will there? Short answer, no. Long answer...no. Seriously, that may be the most deflating question ever to ask an RTS developer: "So, does your game do all this awesome stuff that you've never, ever hinted at or alluded to?" But there's some good stuff here if you are interested in Word in Conflict.
Q&A with David Polfeldt [massgate]