This was actually clearer in the FAQ posted on gw's website: Dark Eldar bombers re-roll misses and enjoy any other benefits of Eldar bombers. At any rate fighters, assault boats, and impailers do not "miss" and therefore may not re-roll misses.
In 2007 FAQ it says:
"Dark Eldar attack craft re-roll misses and enjoy any other benefits of equivalent Eldar attack craft"
according to this additionally to eldar benefits I get an extra DE benefit.
does it means that:
DE bombers may re-roll any dice when determining number of attacks AND re-roll missed attacks against armor?
DE fighters re-roll 4+ save to remain in play?
DE assault boats and impalers may re-roll 1's? 
1: You may, as Eldar, re-roll the to hit dice, AND as Dark Eldar re-roll any missed damage dice.
2: DE fighters get one 4+save to remain in play, since this is not an attack that can miss you may not re-roll the result.
3: DE assault boats and impailers like all assault boats do not roll to hit, they roll a hit and run attack, on a result of 1 the attack fails not misses and therefore may not be re-rolled.
In the FAQ 2010 however it states:
Dark Eldar ordnance and attack craft enjoys all resilience and re-roll benefits Eldar ordnance does, and they behave in the same manner in all respects. Pg 25 faq2010
This removes the re-roll misses statement and clears everything up nicely.
