I don't have much to post on this yet. First, I will say that the setting information, all that has gone before, will stay the same. That includes the Near Star List. It may not be accurate anymore, but it is close enough, and too much has been predicated on that map to change it now.
I'm working on the rules-intensive portions first, including character generation, world generation, and vehicle and starship design. After that comes the building of the setting, taking what has gone before and adding 20 years of history to it. New colonies and the results of the Kafer War will be dealt with, and there will be new opportunities and new threats to challenge the players.
Along with, of course, new weapons, vehicles, starships and equipment, all D20 / T20 compatible. Some of the old favorites from 2300 AD will be there, along with new stuff from the past 20 years of setting history.
As for play-testing, I can't speak to that at the moment. I'll have to wait until the project is farther along. But thanks for asking.
This is a great project to be working on, and I'm really looking forward to it.
Colin Dunn