Original Article (06/05): It looks like Google is launching Flight Search in Canada in both English and in French. The company announced this in a blog post on the ITA Software blog, but the post is currently not live. The feed, however, did come through my RSS reader, providing the news.
If you go to google.ca/flights, there's nothing there at the time of this writing (the U.S. version is google.com/flights), though you do get flight results if you search for a flight from google.ca:
"Now you can find and book flights from Canadian airports, complete with all the benefits of our Flight Search product," says Google Travel Commercial Director Gianni Marostica in the missing blog post. "You can use Flight Search to book travel to over 500 international destinations. If your ideal destination or airline isn't yet available, don’t worry -- we're working hard on expanding our global coverage and adding more routes and airline partners in the future. Our goal is to make booking travel as fast and enjoyable as possible."
Flight prices for Flight Search in Canada, of course, are listed in Canadian dollars.