Microsoft Office has split into two distinct personalities, Office 2013 (which you get via a CD) and Office 365 (that comes via the browser and the cloud). The two share several common features and will make it easier for federal government users to collaborate without having to serially email documents back and forth. There is also tighter integration into your Microsoft account for reading emails and adding contacts and calendar entries.
For more on my review of MS Office Pro Plus 2013, read it in FedTech Magazine’s latest issue here.