The Jubilee has put the monarchy in the spotlight and shown Canadians and citizens of the other Commonwealth Realms something they can celebrate. The media has also covered the points of view which criticize the institution. I've recently noticed two recurring themes in republican arguments:
First, there seems to be a fundamental but apparently common misunderstanding as to how our head of state is chosen. The incorrect version is that by an accident of birth then Princess Elizabeth was deemed "better" by some nebulous criteria and on this basis was consequently acclaimed to the office of head of state. I suspect this is an attempt to portray the succession mechanism as based on some medieval superstition without being honest enough to explicitly suggest that as the process, since then the fallacy would be self-evident.
In fact our head of state is chosen on the same basis that the head of state of nearly every country, elected or unelected, is chosen. Queen Elizabeth is head of state because the law says she is. Not superstition, not divine right, not popularity, not vague concepts of entitlement or social hierarchy, and not subjective opinions on her worth (whatever that might mean) as a human being, but specific and unambiguous legislation.
In fact Her Majesty is a hard-working dedicated public servant who perhaps is better at her job than many of her officials, but that is a happy coincidence, not the basis of her holding the office. As a matter of law it makes no difference how many or how few people feel that she is good at her job.
Second, the thinking behind the arguments for an elected head of state is apparently that the Constitution would be perfect if only it had one more politician. (Personally I'm not convinced that we suffer from a shortage of politicians.)