If you didn't already know, recently it has been found that the following macro:

/stopcasting

/cast Slam

/Startattack

if used AFTER the remaining time of your swingtimer minus the time of your slam (ex: If you talented your slam to 1.1sec and you start casting your slam when there is less than 1.1sec until your next autoswing, when your slam hits you WILL auto attack) will result in an auto attack immediately after the slam. Basically if we could get a different color (kind of like hunters get for theirs) for when the window is allowed to slam. Sorry for any confusion but please try the macro and you'll see!