A bit late for me to respond here... but yeah any motor vehicle brought in to Canada must meet the safety requirements. So you'll have to do get some kind of import inspection done on the vehicle where they'll either confirm that the bike meets the standards, or they'll bring it up to standards. Went through the same process in 2007 when I moved back to Ontario from Michigan. Granted, that was with a car and not a motorcycle, but still... Also it's the responsibility of whoever imports the vehicle to make sure that it conforms.
EDIT: You said you'd be buying it from a Canadian dealer. If the point-of-sale was in Canada, and they brought the bike across the border, ensuring that it meets the standards is their responsibility. However, if you buy it in the USA and bring it across, it would be your responsibility.
* The above is NOT legal advice. By acting on anything I have said, you assume responsibility for any outcome and consequences. *
http://www.OntarioTicket.com OR http://www.OHTA.ca