I can still use backstab with 1.04 as much as I did before, although movement is a bit restrictive, they should have limited the pivot rather than remove it altogether.
With 1.03 the following things killed me:
Backswing - No matter how good you are, this move will get you eventually.
Kick - I'm on 56k, and as any 56ker will tell you, the only way to win a kick fight on 56k is to do the first kick and hope it kills. There is no way for someone with my pings to win a kick-fight.
Lightning - Well not really, Lightning only kills me if someone is lucky enough to find me when absorb has just run out and i'm on low health and mana.
Pull/Push - It happens to the best of us, but careful observations and taking few risks usually stops this.
DFA - For some reason even If I dodge the attack with plenty of time to spare the move will literally "drag" me back under the blade.
As you can see a lot of the times I am killed is due to my insane pings. I also have no idea how good I would be with low pings. But in a few months i'll be at University with high-speed internet so i'll finally be able to play well.
. Backstabbing is still possible and though it will still take us a while to get used to the dynamics of its restrictions, I feel people will be whining about it again quite soon