Earlier this year, Microsoft announced plans to move all users of its Office 365 service to an upgraded version in 2013. Queen's will be undergoing the change on September 2, 2013, just before the start of the new academic year. The upgrade will affect all undergraduate students who receive their Queen’s email and calendar service using Office 365.
It is expected that there will be no service interruption during the upgrade; however if logged-in users find that they are disconnected when the change takes place, they can simply log in once more. There will be some noticeable changes to the interface and overall look and feel; but basic functionality will remain the same. One of the primary reasons that Microsoft is releasing this upgrade is to make it possible to roll out smaller, more frequent updates in the future.
More information about changes to the Outlook Web App, can be found on this page on Microsoft's website.