Hopefully they do the Timothy Zahn stuff. As much as the prequels sucked, there's been some good Star Wars fiction outside of the films.Entertainment Weekly seems to think that the new trilogy will focus on Jaida and Jacen Solo and Ben Skywalker. That seemingly would make a lot of sense since Luke, Leia, and Hans all would be around for much of the trilogy, but wouldn't be the focus, and all three would be old enough that they could be played by the three original actors (with some minor age editing).
(Yes, I am a nerd.)
EDIT: To remove some spoiler esque stuff, in case they do actually go that route.
I'd like to see them go that route, the question will be how far in the future do they go. Spoilers in White text, highlight to read.
I mean, as a extended universe reader, the novels where Jacen, Jania and anakin where they were 1) the focus of the books and 2) between 8-16
were just god awful. Teenage angst on a galactic scale.
Now, when they grew up and started getting to go do important, Galaxy shaking stuff the EU really took off. Jania now is one of my favorite Character in the EU.
Also, it will be interesting how they address both Mara Jade and Ben if they go that route. Mara Jade is fairly well known, for a EU character, but you'd still probley need some extensive backstory on her to bring her into the movies. Would they want to spend some of the first movie developing the "this is a secret jedi assiasian no one knew existed who has been trying to kill Luke for years but now loves him" story?
And Ben skywalker came real, real late in the book series, due to Luke and Mara having problems having a kid. I mean he's what, 12 when he becomes Jacen's apprentice in the EU? and Jacen is like 25 at that point.
They could just age him though, that would be an easy one to fix
I think they will spend the first movie going very quickly through Jaida and Jacen aging, Luke and Mara meeting, and probably end it about the time Ben is born. The second movie will probably be Ben becoming an apprentice to Jacen and moving in that storyline with the climax being what should be obvious. The third movie will then be the full on good v. evil battle.
At least that is how I would do it and that would seemingly make sense. Though if you did that you would either have to recast Luke, Leia, and Hans or do some fairly dramatic CGI to young them up for at least the first movie (probably could get away with it in the 2nd and 3rd with just makeup).
They could also just start the first movie at the time when Ben become Jacen's apprentice without much backstory and just do the backstory in sort of a flashback mode throughout the movies. There is certainly plenty there for three movies and then you wouldn't need to recast Luke, Leia, and Hans at all as they would be nearer to their actual ages now.