It seems that Drell the Blackjack doesn't want to spawn for the quest "Take Down Drell" in Three River's Village. This quest is offered as a pickup off the bandits while performing the quest "Bandits in the Hills" I did a little bit of research, and found that he apparently spawns after a server restart.. but otherwise? He doesn't seem to want to appear at all. Something to look into.
I know he worked about 1 or 2 months ago. Make sure you are across the road from the second bandit camp and down a little ways.