I think the effort that this would involve - well, it would be hard. And the outcome - well, there are thousands of us hungry folks out there (swarming on dubious HITS).
But - I still support it. I think anything that can be done to unite folks and, perhaps - strongly 'not recommending' a particular HIT (Based on poor pay) - is a good thing. Many people would follow along with the recommendation (TO does this, to some small extent). Those that do the HIT anyway, well, that's not quite the point. It's more that requesters know that there is a cohesive group on mturk that DO watch and track (and recommend) based on pay.
I would think to start this convo you'd have to find a way to start a conversation between boards (and with folks on TO).
I'd join in