Although it's not out yet and it's not actually a MOO game, Paradox is working on
Stellaris and it looks absolutely amazing. They're taking the kind of in-depth grand strategy approach they use in their other games (
Crusader Kings,
Hearts of Iron,
Europa Universalis, etc.) and applying it to a sci-fi space empire setting.
Reportedly, it will be detailed enough that you can, for instance, "uplift" pre-warp species and annex them into your empire--but they can potentially destroy themselves in the process. Another example: once your culture unlocks genetic modification, your people may begin modifying themselves to the point that you develop subspecies which may view themselves as superior and try to overthrow you/split off into their own empire.
The stuff that's been demonstrated so far looks extremely impressive and interesting, and like most Paradox games, warfare isn't the driving focus, but rather managing the politics, culture, and economy of your empire. (Of course, warfare is still a prominent feature.)
