This link at
www.regulations.gov seems to indicate WN was granted authority by the DOT to fly to Canada effective April 2009. Reading the PDF link on the site seems to indicate authority from Canada may be a separate process.
http://www.regulations.gov/search/Re...0000648096e346
If the above link is broken, try searching for Docket ID DOT-OST-2008-0392 at
www.regulations.gov.