The last episode written by jms was "End of the Line," further comments from jms revealed that it would have required lots of special effects to be produced, with that clue in mind I'm guessing that maybe the Drakh have a massive attack on the Earth Alliance. In retaliation, lead by the Excalibur, an Earth Alliance fleet takes the offensive...
More ideas coming soon...
"I did what was necessary. There were casualties on both sides of the war. The difference is, when you win the war, you're a hero; when you lose, you're a war criminal. There were things I did that the current administration disapproves of because they are the heros and I am the war criminal. But if the tables were turned, I could easily accuse them of the same crimes. No, I'm not going to turn myself in. I did what was right. They'll never be able to prove otherwise, because in the end, everything I did was for my people."