During shutdown I noticed a few error messages:
Cannot stat /etc/rc0.d/k91wlan
Cannot stat /etc/rc0.d/k73apmiser
Cannot stat /etc/rc0.d/k05ultrabayd
Do these messages have anything to do with that wireless button?
However, on a brighter note, rfkill is working! But I still look for the hotkey (fn+f2) to enable/disable wlan and bluetooth.