Merits are an obvious reward in the current structure, but can we use the trust system as an encouragement for consistent good posting to support the forum? My initial though is that posting has nothing to do with trust. So if I participate in the new trust ranking, how can I use that to encourage quality members.
If that is the case then you can always try to to put scam hunters into your trust list. If you look at the scam accusation section you will see a lot of dedicated people posting their findings on whether or not a scammer is trying to scam a people, they also post their bounty abusers as well and a lot of other things. These people at least can be a start for your own trust list as they do deserve it with the effort they are doing.