Lightdm tip.

[Sergio]

Just a heads up that now with the latest update auto-login is working 
properly and also we can choose the default session if we have more than 
one desktop environment/window manager installed.
Just edit the 'user-session' entry in /etc/lightdm/lightdm.conf
For Xfce:
user-session=xfce

(also needed for auto-login to work, or instead one can link 
/usr/share/xsessions/xfce.desktop to /usr/share/xsessions/default.desktop)