The game engine for SC seems pretty solid and reasonably versatile from what I’ve seen so far.
I assume this is unlikely to happen because of the cost and paperwork of aquiring intellectual property rights to other genres, but I can see Star Conflict easily accomodating games for titles like Star Wars, Battlestar Galactica, Star Trek, Homeworld, etc.
As this is an MMO, that tends to rule out the possibilty of any kind of community modding, as much as I would love to see that, it could never be officially supported because of copyright infringement and access to modders would need to be limited so as to not expose the inner workings of the client-server protocol, or possibly exploits in the system.
But yes, implementing of modes is hard, considering SC genre.