The following improvements have been implemented:

You can now use the Networking circles app in your event rooms.

In Look and Feel, you can now add room and categories to the navigation bar. You can also upload custom fonts to reflect your organization's corporate identity/design.

If your event is protected by a guest list, you can completely personalize the content of the calendar invites that are emailed to participants.

Note that if you're using the Virtual Events API, you should add a header Content-type to "application/JSON" to your API request.