I think we should expand the range of equipment offered to somewhat emulate the pve model. For example add a higher value pvp currency (elite wolf mark?) with a weekly cap.
This may increase pvp participation as players want to cap their pvp currency every week, while preventing anyone from progressing too quickly and quiting once they have their rewards. The restricted pace would force players to participate every week for entire patch cycles in order to complete their gear sets.
Another option is to add a weekly quest at Wolves' Den Pier which rewards a unique token or augmentation item. The objective of the quest could be to participate in 5x The Feast matches and 1x Frontlines roulette. The exchange of this weekly token in addition to several wolf mark tokens (cost say 5,000 wolf marks each) would reward special equipment with glow effects.