According to a Launchpad bug report, a new application, called Xfce Panel Switch, should be included by default with Xubuntu 15.10 Wily Werewolf. The package is currently in the Wily new queue.
Xfce Panel Switch is a layout manager for the Xfce panel which allows users to easily backup, restore, import and export the Xfce panel configuration:
The bug report mentions that the app should also allow switching between one of the included default panel layouts (Xfce, Classic Xubuntu and Xubuntu Trusty) however, there are no predefined panel layouts included yet with the package I tested.
In Xubuntu 15.10 Wily Werewolf, Xfce Panel Switch should also be accompanied by an Xfce Panel patch that allows launching this app from the Panel preferences:
"The initial testing with our QA team has completed and we have decided to include this for 15.10 if possible. As a new application, Debian Xfce is not yet interested in including this package", mentions the bug report.
Currently, the app is available for testing in the Xfce Panel Switch PPA (without the patched Xfce Panel) for Ubuntu 15.10 and in the Xubuntu Staging PPA (with the patched Xfce Panel) for Xubuntu 15.10 and 15.04.