Okay, so we've talking about the risks of Omega and what some things could be like due to its use. But Alexman talked about just grabbing Omega and seeing how stupid he could be with it. On that note, lets say that happened.
Now, the whole galaxy is suffering from Omega. No warp travel at all, systems that were once a part of larger nations are now years apart. What happens and to who and how do they deal with it?
Borg... well I don't see them changing much myself. I don't think they give a damn about travel times if.
However, I spent a lot of time studying Klingons for the Trek Sim Alpha. Looking at how broken up they are as a population, either being a warrior and fighting or being just some serf. Serfs, or more likely their worlds as a whole, being traded or fought over as resources for Warrior groups. Basically it would boil down to the Klingons becoming what the Orks are in 40k. A race that battles itself until someone comes along that's able to united a large group with the intent of setting out to invade some other world they know of from their pre-omega maps.