Export to XML is now available on all items where export to CSV is available (e.g. Hardware, Software etc.). Export to XML is useful in those scenarios where a complete dump of all the relationships of objects is required. For example, Computer CSV export has a limit of 10 storage devices and network connections. When you have more, XML is the way to get the data. When you need a file for parsing in an external program, XML is better than CSV.
As you can see below in the screenshot, the XML is now another options to choose from the dropdown list.
If the selected set to export if less than 200 items then the export will be to the screen. If it is larger than 200 items then the export will be by batch process and will be sent via email.