I have recently installed Arch Linux and GNOME 3 on my new laptop and have a problem whereby
nm-applet is not showing in
gnome-panel, unless I manually restart the NetworkManager daemon.
I found the answer with help of the Arch Linux Forums:
I tried to start the networkmanager daemon before the dbus daemon, which does not work. Changing the order solved the problem.
Another way is by adding to startup apps: