It would be great if reviews could have 'Watchers'. That is, people or emails that aren't really designated as reviewers, but can see comments being added. This is particularly useful in the case of mid-size teams. We have around 9 people, all of which should have the ability to see reviews (because it's eductionally useful), but ideally not all would be considered "Reviewers". Otherwise (if all are Reviewers), reviews can be a real PITA, with a lot of people going to town on the review.
If we could designate a default Watcher that was our dev email list, and each review could designate some specific reviewers (say, 2 or 3 people), then it would be a closer integration between the author & reviewers, but watchers would be able to see what's going on and optionally join the review if necessary.