It's actually difficult to say what the key ones are. Maybe I'll deal more with what should be done, because it will probably be the same steps no matter what the issue is.
We've talked about tax evasion a lot. We've talked about tax avoidance. Strictly speaking, tax avoidance is reducing your tax legally, at least under the international definition. The CRA uses a slightly different one.
Then there's aggressive avoidance. I think the big rule there is the general anti-avoidance rule. That's the rule that will apply if your tax position technically meets the rules but is outside the object and spirit of the tax rules. I think that'll be something that the government will be looking into more.
Using Quebec as an example, Quebec's consequences around the general anti-avoidance rule go further than the federal rules do, so I would imagine that would be something the federal government will be looking at when they do their review.