Just thought I'd chime in here since RoD is kind of my baby (and David's, of course).
I didn't want the Traveller conversion to just be a straight transition, and certain design decisions were made.... The first thing I addressed was the fact that the original book was actually written very quickly. There were a few rough spots in the text that I wanted smoothed out, so the first thing I did with the Traveller conversion was do some smoothing and clarifying.
Satisfied with that, I then went to the reviews that had been done of the book. So far every review has been good, and I'll publicly pat myself on the back for that now, but as with all reviews, there were points where they felt that the book could have been better. I take reviews seriously, so I expanded the text to include some important points. Planet descriptions have been expanded so that there is some information on the most planetary governments. This includes names of leaders and political concerns.
The other major thing that the reviewers said it needed was a chapter to help GMs (or referees in Traveller) design scenarios. So I added a "How to run Reign of Discordia) section that addresses things like the feel of the setting, and what sorts of plot elements you might design around. This wasn't in the original book because I thought it was rather obvious that it was supposed to be an "everything and the kitchen sink" type of setting, catering to the space operas two to three decades ago. That said, I was more than happy to offer up some advice and hopefully people will find it handy.
We do have tentative plans to update the True20 version with the new material and put the new and improved cover art on it.
Finally, getting around to design decisions, I felt that it was important to emphasize on the setting itself without getting wrapped up in a lot of the fine details. In other words, don't reinvent what already exists in Traveller! For example, while I replaced the personal weaponry, I left the armor from core Traveller intact, so all the new armor is intended to add to the existing stuff. Much of the equipment from the original book, which had originally been converted from D20 Modern, was converted over to Traveller, but I always looked for something in the rules that already covered what I was doing first.
Finally, since I know that ships are near and dear to the hearts of Traveller players, I wanted the Reign of Discordia ships converted in such a way that you can use them in a regular Traveller game. Likewise, you can also take ships from any Traveller book and use them in Reign of Discordia. There are a few differences, such as the fact that there are no fuel scoops in RoD, so you have to actually purchase your fuel. Also, RoD has tractor beams where Traveller does not. Minor differences aside, I wanted them to go easily between games. To accomplish this, I enlisted the help of some of the people right here on the boards and I'm pleased with how things are turning out.
So to give you an update, the manuscript is still in editing, though I expect that it will be done soon. The other thing we're waiting on is the final ships to be added to the game. Again, this is being worked on and they'll likely be done soon. From there, it's in Dave's hands and it's up to him to decide whether to release the PDF ahead of the printed book.