I think that the expansion will contain at least the Tie Bomber and B-wing. The following is what I expect these fighters will be built like.
*** Tie Bomber
2 3 5 0, Target Lock, Focus, Evade, two missiles and one bomb.
The model will cost 15 points for a base unnamed pilot to 24 for named pilot with medal. No barrel role because the Tie Bomber is harder to manuver.
*** B-winig
2 2 5 4, Target Lock, Focus, Evade, two proton topedos and one cannon.
The model will cost 21 points for base unnamed pilot to 28 for named pilot wiht medal. Because the the B-wing wing rotates around the cockpit, the ship can take an evade token as an action. The B-wing will also get one addition agility dice compared to the Y-wing because of the rotating wing.
Now for the wish list.
I would like to see a missions box, something a little like the starter box. This box would include severval new missions and tokens for the mission. It will also include some unique pilots for already existing ships and some new, unique, and addition hard to get upgrade cards. The set would also contain another set of movement and measuring rulers; would be nice if they were plastiic instead of conpressed cardboard. Most importantly the box would contain two fighters. An Imperial shuttle and a Senotor's shuttle to be used with the missions.
One mission I could invision in this set is the a mission where the Imperial player is trying to protect the Imperial shuttle while the Rebel player is trying to Ion cannon it X times to steal it, say for an elite mission to land on the planot Endor.
Those are just some speculations, feel free to make some contributions to what you think Expansion 3 may look like.