I guess there just isn't enough of a Canadian player base to justify any effort from ANet. It sucks. If they gave us a 20% deal I'd drop a significant amount on gems.
The current Gem Card sale offer is through Best Buy. Best Buy in Canada does not have GW2 gem cards. If you're only going to offer gem sales to the US, just say so. Silly me, I thought that Canada was a part of North America....