So things aren't going to go too well for Murphy, after Rebel. I also am worried about his family back on earth. I know that RFC (and Fox) have the extended story plotted out and ending with Terrance Murphy as the first emperor of the Terran Empire. (I don't know if that is the name that it is called, but it will do for now)
But it looks (as far as I can see) that Murphy has an extremely long row to hoe. And there's THREE bad guys to deal with, the first being the five hundred, but there's also the League, and lets not forget about the Rish.
I really can't see this being anything other than a long series, a lot like Honor Harrington. Well, maybe not THAT many but still a lot of story to be told. Hopefully Fox will be able to finish it, because at the standard rate that novels are written and published, I find it unlikely that RFC will still be working that long, especially with all the OTHER writing commitments he's obligated himself to.
That's why I said at the beginning that I'm sure that the basic outlines have been plotted out already, because it will be years (and many books) before Murphy is crowned as Emperor Murphy.
And, knowing RFC's penchant for long stories, I wouldn't be surprised if he hasn't alread penciled out a few outlines about the Rish/Human conflict. Oh, it's good to be a reader!
I guess mostly what I'm trying to say, is that this isn't simply a trilogy, it's a LOT more!
Edit
It wasn't too hard (once I'd thought about it for a minute) to figure out how RFC is going to get Murphy's family out of the sticky spot they're in, and that was a relief, I was worried about it. But there is still a LOT that will need to be addressed in the journey to empire, and I for one can hardly wait. Unfortunately I fear it will be yeats in the making. Oh well patience is a virtue.