Just to make life easier for people subscribing / unsubscribing from topics. Rather than having to go to the bottom of the page now. This can be done from the Profile pane of any post.
Its also really easy to subscribe / unsubscribe to/from specific forums, not just topics by using the links at the top and bottom of a forum page:
and
Subscribed topics can then be managed under
User Control Panel -> Forum Subscriptions