So apparently Siri works in Canada but is missing some key features. For example, it won't provide location/direction information and it won't provide you with restaurant information either.
Hopefully those features get added in later.
The best quote from this article is this:
" I asked Siri to marry me and she said she was flattered but wasn’t permitted to do so."
Siri is still in Beta. And just like Googles streetview feature, it'll take time until all of the countries are listed with all of the features. But i gotta say, its one sweet feature.
Just for a laugh, ask Siri "whats the best mobile phone to buy"