It is now possible for events from one Events page (calendar) to be included on your other Event pages. This means that you will be able to have an event appear on multiple calendars but only need to add the event once. It also means you will only need to edit the event in one place and the changes will appear on the other calendars.
One common use of this feature for the creation of a "Master Calendar" on the site. A calendar that includes all the events from the various calendars in your site.