Notable changes in 4.10 are -
A new application finder
xfce4-appfinderre-written from scratch that combines the functionality of the old appfinder and xfrun4. It also allows creating custom actions matching a prefix or a regex pattern.
The Xfce panel
xfce4-panelhas acquired a new viewing mode called Deskbar mode that allows you to create wide vertical panels suitable for a wide screen setup. You can now place icons and application shortcuts in multiple rows in the panel.
The sessions manager
xfce4-sessionhas been simplified. The compatibility check boxes (for GNOME and KDE compatibility) only enable services which have to be started before other applications. More over, the compatibility services can be started independently from each other.
On the settings side, the two processes used for applying settings have been merged into one - xfsettingsd, which now handles all system settings.
xfdesktop, has gained support for single-click operation, automated background image cycling and thumbnail rendering.
Improvements have also been made to the way Xfce handles mouse and touchpad.
For the screen shots and more details, do take the tour of Xfce 4.10.
[Source : Xfce.org]