If it turns out that Nick Berg, like the Japanese Leftists a few weeks ago, was over there offering to be a pretend hostage, that would lessen my sympathy for him. As for the father, his near instantaneous politicizing of his son's hideous death is despicable, in my opinion.
Absolutely no evidence of that yet and I don't think there will be. I still would have sympathy for him even if there were, given that he was given a death that only an arch criminal would deserve and that no civilized society would impose. But that's me.
I think Berg the younger was a naive adventurer, perhaps "liberal," we don't know, but likely with the notion that he was capable of face-to-face diplomacy with any hostiles he might encounter.And, as pointed out earlier, he may have been led to his death by perfidious "friends," ala Danny Pearl