Doesn't look like they've added any coverage in Canada yet. USA (even Alaskan cities), much of Europe, Australia, New Zealand and Japan are covered.
I used to develop software for the company that created the technology. Google's implementation is as still pictures, but the cameras actually capture it as
full-motion video. It's pretty cool when you view it that way, it's like you're sitting on the car (or under the helicopter, or walking around) while it moves along and you can look around.
In case any fellow nerds are interested, the camera is about the size of a cantaloupe, and has 11 lenses pointing in all directions (the 12th one would be where the mount is). The genius of the system is stitching the 11 video images together into a seamless mosaic.