There's clearly a disconnect between the flight deck and the ground crew.
I'm thinking that getting representatives from both groups together is critical, as stated above,and that there should become an international standard.
But I think the first thing that needs to be expressed to the ground crew is that the flight deck can't see below them, to the left, to the right, or behind.... the flight deck can't see if anyone is in/around the aircraft.
Interestingly, this is not a problem backing out of the gate because someone is driving the push-back cart and they can see all around the aircraft.
So we're going to see this problem occur during de-icing more than anywhere else, when the de-icing is not happening at the gate - and maybe that's why some airports went to gate de-icing in the first place - if the de-icing is taking place at the same location in the taxi then there could be a "supervisor" in a jeep who drives in front of the plane and moves only when it's all clear.
At any rate, there needs to be a standard in place the prevents this type of thing from happening again. It gives a really bad impression to the public when a plane runs into the ground crew at 2 miles an hour.