Last time I went to Canada all I needed was a Passport. I do not even remember showing it to the Custom Official. I drove up said hi and they let me through.
As far as I know it was/is the same for Canadians visiting the US. Except the US border people tended to be d**ks, even to US Citizens.
Canadians do not need a visa to enter the US. And many countries are covered under the Visa Waiver Program, such as many European countries. So no, this does not affect Canadians.