I just tried to connect to the iBook store using my Canadian iTunes account and was surprised to see eBooks in the store. But my surprise did not last long as I discovered that there are no commercial eBooks in the store yet. Only public domain books can be added for free to the bookshelf.
This is rather disappointing for the moment. But it is still early and there are more days from now until the 28th for Apple to add commercial eBooks.
For now I will have to stick with Jules Verne 20000 Lieues Sous Les Mers.