@Fax: Duskblade spell list on the way. :P
When giving a good look at the RAW fear system, I'm going to redo fear entirely. But I don't think Concentration is a fair check for fear as not all the classes. But if a character could use Concentration (by sheer force of blocking it out) or Intimidate (by bolstering yourself against fear through your own dealings in it), most classes have either Concentration or Intimidate. Hmm, I'll have to ponder on all this. There will also be feats for most types of classes to handle fear a little better, and even draw from it (Dreadnaut feat added).
And I've addressed the Dread-Necro-animate dead-lockdown-when-multiclassing-at-level-8+ issue in Class Fixes at the original post.