I know that in the very early days of PIPEDA there was a lot of talk about trust marks and trust seals and so on. People tried them. They haven't really gone very far. I think there have been concerns about the counterfeiting or faking of trust seals and trust marks as well. I'm not sure how viable that is as a solution.
There are interesting technological developments as well. People are working on codes and apps, for example, that will scan and rate privacy policies, so I would be hesitant to go with a trust mark solution when there may be other technological tools that would be more useful and more effective in terms of helping consumers understand what the privacy policies are.
That said, I know that for some time we've been talking about privacy by design and privacy by default. Those are important principles. It may take amendments or changes to the law to get people's attention on them.