Its very basic, I offered to help re-write some of the events and files etc to add generals to the game with new portraits, however what they wanted to do was to keep the vanilla game and add the portraits we all made in this forum to get rid of generic portraits in the main campaign. You will still have generic portraits in the smaller campaigns, especially for Union, just because of the sheer number of them and also since some generals were not well known and don't have good pictures. But in the main campaign there should not be any generic portraits except maybe one Union Naval Officer Chase, which for me is awesome. There was also some corrections, i.e. using the correct portrait for Speed Fry.
The other cool thing is that even though they did not want to add new generals and re-write events, for those of us who know how to add generals there will already be included numerous additional generals, some very popular ones, that did not appear in the vanilla game. So all you have to do is make the mdl/unit files and add the generals and their portraits will already be there as long as you point to the right portrait files. I can always put my own mod out here with all the generals already added since I have already made that MOD for myself with all the general portraits from this patch.
I hope that makes you guys happy, having the main campaigns without generic portraits to me is a big deal and there was a lot of hard work we all put into adding them...and then having some finished portraits of new generals to add at your whimsy is pretty cool. So hopefully they release the patch soon for download on the website. I have the patch but I was under the impression they were going to do a formal release, hopefully even on Steam. I'll let you know when Phil Thib gives his final word.