I think the idea for a blacklist/arbitrator is an excellent idea, however, there are some important points that would need to be established.
Conflict of interest
There site should not be used to promote anything. It should be solely independant.
This way, it would guarantee no conflicts of interest occur.
Charter
There should be clearly defined criteria as to what puts an affiliate program on the blacklist.
This way, it wouldn’t be open to abuse. Ideally, the criteria would be debated in an open forum between affiliates and operators.
In an ideal world the site would be run by someone was neither an affiliate nor an operator, however, considering it would essentially be a loss making enterprise, I guess it would be quite difficult to get someone to do it!
Theres a lot to consider.