If you rely on your phone service for internet access, my understanding is that it can be complex to deal with non-Canadian phones and Canadian ISPs. Not impossible, but it may be different.
Even if it isn't complex, it will probably be more expensive than it should be.
But WiFi should work normally.
This thread is full of stuff I can't understand, and is at least three years old, but I think that it might be on point: http://www.flyertalk.com/forum/canad...martphone.html
In the past I think there may have been more problems with unusual system standards, but I believe that most of the networks now use systems that are more mainstream.