There is a mechanism called deliberative polling that I was going to mention. It hasn't been used all that much in Canada, but it's more feasible now with the increasing use of the Internet in polling. If you were to draw samples, the way you do for ordinary public opinion polls, and then extend them by having people deliberate the issue online and exchange thoughts about it, the technology is there to do that.
There are several good books in the U.S. written on deliberative polling, and it has been used in various places, but it has been on a model a little different from an Internet-based model. I could, however, see some of its principles being extended, because polls have some credibility, if the sampling is done right. If you could get a sample that was not just an instant snapshot of answers to a question but was based on some kind of built-in deliberative process that took place over a period of time, I think that's a possibility we might look at.
Someone closer to the polling industry than I am might have better advice on this than I.