Typically when new software releases come out, there are always a few really key improvements that really stand out. Many times, it is a cool new modeling feature, or maybe an entirely new approach to design. In Inventor, this might be like the addition of Freeform Modeling or Direct Editing as examples. Unfortunately these are features or techniques that might not be applicable to many users.
If you are using both Autodesk Inventor and Vault together however, you should probably pay attention to this one: The Vault status icons in the “recently used” area. These icons now clearly identify the current Vault status of one of your recent files when in the Inventor “Open” dialog box. Is the file checked out? Is the file checked in, and up to date in my workspace? Has someone else modified the file since I last worked on it? Have I checked in my latest development ideas or new parts yet? All of these can be determined simply by noticing the Vault status bubbles in the “Open” dialog box.