[thomasbk]

If the large pools make a deal, any transactions they don't pick up will only ever get accepted after a very long wait. Hell, since they control >50% of the network, they can simply make the new transaction fees a new rule and force lower transactions to not be accepted by anyone (i.e. ignoring those blocks, like a 51% attack.)

Policy by economic (mining) majority could be an issue in the future when the policy directly determines the profits of that majority.