Just thought I'd compile some info we have from previous previews, that I haven't seen anybody post yet; I think a lot can be learned about many of the pilots in the expansion packs with a little deduction. This all comes from the "Expand your Fleet" preview images:
Unique TIE pilot "Mau[ler Mithel"]
After you move, ea[ch squadron adjacent to?]
you suffers 1 dam[age.]
Brace, (Scatter?)
Unique TIE advanced pilot "Dar[th Vader"]
While attacking, e[ach (critical?) you roll deals?]
1 damage to the d[efender?]
Brace, (Brace?)
Unique TIE Interceptor pilot "Soo[ntir Fel"]
After a squadron you [(activate?) (at distance 1?)]
performs a non-Counter [attack, it deals 1?]
damage if it did not [(roll any hits?)]
Brace, Scatter
Unique TIE Bomber pilot "Major Rhymer"
Friendly squadrons at distance 1 can attack
enemy ships at close-medium range using all
dice in their battery armament.
Brace, Brace
Unique X-Wing pilot "Wed[ge Antillies"]
While attacking a [(squadron at range 1, you?)]
may add 2 blue d[ice to your attack pool.]
Brace, (Brace?)
Unique Y-Wing pilot "'Dut[ch' Vander"]
When a squadron [?]
damage, you may [?]
the activated side. [?]
suffers 1 additional [damage.]
Brace, Brace
Unique A-Wing pilot "Tycho [Celchu"]
You can move out of [engagement and]
attack ships even [while engaged.]
Brace, (Scatter?)
Unique B-Wing pilot "Keyan Farlander"
While attacking a ship, if the defending hull
zone has no shields, you may reroll any
number of dice in your attack pool.
Brace, Brace
I've tried to be as faithful as possible with my transcription, filling in what seem obvious gaps in the square brackets, taking educated guesses with ? and (). The Rebel pilots have only one Scatter token among them, while the Imperials have 2 (And we can clearly see Fel has 1 Brace token). I have some guesses as to what Dutch Vander could say, but they all seem nuts; I get the impression he can activate a squadron he hits, and/or deal extra damage to them, but making a squadron take an extra hit and skip a turn seems too strong unless there's a drawback or he costs a bunch of points.
Vader obviously has some mechanic for dealing extra damage, as is fitting; it could be something other than rolling criticals that triggers it.
Fel doesn't say "friendly squadron"; he also deals extra damage to somebody for something, he could deal damage to enemy squadrons who attack him but miss?
Wedge obviously gets 2 bonus blue dice for attacking something; squadrons makes far more sense than ships, although he certainly has taken on more than his fair share of those too.
Tycho, Mauler, Keyan and Rhymer I'm all pretty confident about; if I'm right, Mauler Mithel seems like a neat way to deal an extra point or two of damage over a game, as moving adjacent to one or more enemy fighters when moving into engagement shouldn't be too hard, and lines right up with his preference for close combat from X-Wing.