I was shocked when I heard the news of this. I would say I am upset, but it hasn't really changed my life. I was a fan of a few of his movies and it's a shame he died so young.
It seems to be that people only really feel upset for lives lost of people that they knew in some way. Whether this be in real life, through the media or internet etc...
I am emphatic to those who die everyday injust, but you can't let every single person who dies affect you. When some dies who you feel you have some connection with (friend, entertainer etc) then you are more prone to feel emotion toward them.
I think this has already been brought up, but if the lead singer or whatever from your favourite band died, then you would probably feel some sort of emotion. It may not be floods of tears, but you would be upset.
Those who were fans of Heath Ledger's acting would feel the same way. No more hate please.