Well, I just finished readling The Unifying Force last night.
I like how everything ended.
On the CD that came with the book there is a transcript for a round table session with the people responsible for NJO, including the writer of the last book, who has been heavily involved behind the scenes. Anyway, they all agree that it was probably a mistake to have so many different authors involved in this story. There were a lot of loose ends throughout NJO that just kinda disappeared.
But, overall, it was a great read.
I don't want to spoil anything, so I will try to be very careful here.
Just incase:
Minor Spoilers
Luke is no longer the all powerful Jedi. Though he is now a master of the Unifying Force, as I would think Jacen is, he was weekened in his battle with Shimra. What exactly this means will hopefully be dealt with in the future.
As for Jacen, he will never be able to summon that kind of power again. He said so himself, so I guess that makes it a rule. As to what he can still do, I am not sure. I think he now knows how to turn tears into a healing potion, but that may have been a temporary thing.
There was no mention of exactly how Jaina was changed, but it is clear that she was, b/c it says she was. I guess that's something that will be touched upon in the future.
By the way, in the round table, they said that Lucas gave them a list of who they couldn't kill. Luke was on that, as I'm sure Han and Leia were, but I'm just guessing. Anyway, they chose Chewbacca b/c he is so difficult to write. To tell you the truth, though, the best writers have never had any problems using him, and there were times in this story where he would have fit in flawlessly, whether the auther would have wanted to write actuall dialogue, or not. Their reason to kill him off, IMHO, is very weak. But, they did, so...
As for Anakin, they actually wanted to kill off Jacen, as they viewed Anakin as the heir to Luke. Lucas said they could not kill Jacen, probably b/c of the twin thing, so they killed Anakin. It was always meant to build him up so much before his death. That's why we didn't see it coming. They consider NJO as Jacen's coming of age story.
In any case, they have given us great characters to read about, my favorite being Tahiri. I hope someone comes along in the future and writes a story around her and Corran.