First off, the Thrawn Trilogy is one of the best SW EU period. If it wasn't we'd not all be here talking and playing SWTOR. It was the first new SW product siince the droids/Ewok stuff. It might have sold well regardless, but if Heir to the Empire wasn't as good as it was then the other books would not have sold as well. SInce they all did do well it opened the door for new merch and new movies and games.
Also EU books are good because when we read them we hear the characters voices and can picture what they look like in our mind, because the movies showed us. If we did not have that to start from, most of them would prob not be as good as they are to us.
The new movie stuff is exciting...even for me who did see the orginal trilogy in theaters. We have to remember its not just our generation or now even the episode 1-3 generation, but future generations that will get to see and experience all the magic we had when we were young, and for some of us still do today
So when the time comes, just sit back, relax and enjoy the trip to a galaxy far far away.