Currently Dread Necromancers of Neutral alignment will use "Turn" undead instead of "Rebuke" undead.
I just had a look at the Heroes of Horror handbook and it seems to grant only Rebuke Undead to a Dread Necromancer regardless of alignment.
Looking at the implementation of Rebuke Undead I noticed that it looks only for the alignment of the character to determine if Rebuke Undead will be used.
Can that also include a check of the class as well?
I know that Neutral Clerics of an Evil or Neutral deity may choose at creation to Rebuke or Turn... is this also an option that can be explored?