I heartily agree with Matt's comments on last night's Wire, and want to reiterate the Marlo-is-a-gigantic-asshole critique. Avon Barksdale, for all his murderous tendencies, was an unsettlingly likable character. You didn't want him to go to jail. You didn't want him to lose. For every instance of brutality, there was another of compassion, a paean to family, a weekly visit to his comatose uncle's bedside. It complicated everything. Marlo, however, is just a jackass. You never see him joking around with friends, or playing basketball, or in any way demonstrating the faintest glimmer of likability. You just want him to get got. He's preternaturally repulsive.
Assumedly, that's a conscious choice on the part of the directors. And with Omar now on a collision course with Marlo, it's hard not to fear that Marlo will be the tool for the show's ultimate, crushing, denouement. Since this match-up places the show's most beloved character against it's most total villain, it's a near-certainty that the villain will brutally and totally destroy the hero -- that, after all, is the show's habit. Just ask D'Angelo Barksdale or Wallace. To make Marlo in any way likable would muddy that water -- it would provide a optimistic out to those who cared for his character. If no one cares for Marlo, if all wish for his destruction, his triumph over the character everyone is attached to will be all the more brutal.