I have to start my answer with a disclaimer unfortunately. The following is not legal advice, and should in no way be construed as such. This is my interpretation on the act, and any advice given should be verified by your attorney if you wish to be 100% safe.
Now that we got that out of the way, I don't believe the new act will really change much in the way we do business.
C28 is there to combat SPAM. Mass UCE (unsolicited commercial emails).
In fact, the government's website even states:
“Legitimate businesses that use email to market their products to Canadians should not be negatively impacted by this legislation.