See also the accessibility roadmap page.
The shutdown code mess currently in xfce4-session is more or less copied from Xfce4-power-manager. We've therefore decided to include Xfce4-power-manager in the core of Xfce so it can provide a DBus service Xfce4-session can use to perform power actions using upower and consolekit.
When the user it either not authorized or the service is not available (platforms that do not support upower and consolekit, like openBSD) Xfce4-session will fall-back to sudo.
Code was cleaned up and all nice stuff it included, but xfce4-session still has it's own upower handling internally.
It seems to be quite common people want to clear they entire session, so maybe we can add a simple button (with question dialog) to the settings dialog, and remove $XDG_CACHE_HOME/sessions.
The tips were heavily outdated and the dialog looked ugly. We've discussed this a bit and came to the conclusing that probably nobody reads the tips so unless we get complains the code will be removed.