What's the main premise of those three movies?
Well I know he orginally had the stories written out (at least, basic idea of who it was, etc.) but I can't remember.
But if we go by the timeline...
Timothy Zahn begins writing the Thrawn Trilogy a few years earlier, about the same time as Episode I is released
The books would have more canonical knowledge of the Clone Wars, and perhaps George Lucas might even put in a mention of the dissapearing slaved clone fleet. Can't remember when that fleet vanished, perhaps it was after the time the 3rd movie is set.
Then, George Lucas works with Zahn to write the movie adaptions of those books.
Preferably as just a name, and not actually ever tocuhing those books, or ever even reading (to limit the possible pollution).
Even in OTL, I would love to see a GOOD director, and a GOOD screenwriter adapt and produce the Thrawn trilogy as sequels to the orginal star wars trilogy.
Episode III was not bad, and I think the only reason Episodes I and II were considered so "bad" is because George Lucas appeared to have a retarded moment of thinking that because his orginal movies were "family-friendly" and many kids remember his movies, perhaps he should make a retarded little kids version complete with a pointless goofball, since primitive races helping the big boys out went over so well with thse ewoks in RotJ, right?
I mean, the non-little kid parts were good, but there were some parts that just made me, a KID, sit back and go WTF is this?
Eh.. this turned into a rant instead of my point:
Thrawn Trilogy as the 3 sequels. YES... YES... OH GOD YESSSS
Besides... there's a blue alien with red eyes who is the commander of the Imperial forces . If they can't make a convincing yet complicated villain out of THAT, I will have lost all my faith in Hollywood.