A note from the Readers' Den at www.canadashistory.ca reminds me:
Now that general book reviewing beyond the bestseller lists has largely vanished from newspapers, magazines and other usual outlets, where is there an opportunity to find books on Canadian history reviewed and discussed?
Well, the online books section of the Canada's History website.
A number of reviewers have developed online projects (like this one) to survey new Canadian fiction, but I don't know of anyone beyond Canada's History attempting that for history or even for nonfiction.