As for functionality, Google focuses on improvements for business users. Admins can now add details about conference rooms, so employees know how large they are, whether they're wheelchair accessible, and whether they have AV equipment. People can also link to spreadsheets, documents, and presentations in their calendar invites so attendees can open them directly from the "event detail" view. You can get an idea of that here:
None of these adjustments are life-changing, but they're useful. Plus, it's always nice to look at something pretty.