On Google’s official blog, Shirin Oskooi, Product Manager said that this move has been taken to save the users’ time to update their Outlook and Google calendar. Now users can update just one, and access any one of them to see their day’s work.

By this users can see their calendar practically from anywhere - home, office, laptop, outlook, Google etc.
However, there is a slight dark side of the news too. The new application supports only Outlook 2003 and 2007. So if you have earlier versions, it might not be helpful for you.
While syncing in process, you can choose between two options, two-way sync or one-way sync. The two-way-sync allows Google Calendar and Outlook Calendar sync with each other. While the One-way sync offers either Google Calendar to sync with Outlook Calendar or vice-versa.