This was discussed in my geology course at UBC. The prof was adamant that this was not a "true" tsunami, that it was a product of specific geology/geometry rather than a true sea-born wave triggered by geological-scale events. I guess he was correct in that this thing didn't have the total energy of a typical tsunami, but it was certainly enormous for those in the local area.
I was fascinated by this article, so I was trying to explain it to my colleagues. I was enthusiastically sketching the bay and glaciers on the chalkboard when I suddenly became very embarrassed, as I realized I was basically drawing a big uterus on the board :S
There are a fair few potential 'megatsunamis' waiting out there. The Canary Islands one could be particularly devastating since theoretically half the island on La Palma could slide into the sea.
Not sure. Part of what makes this one so high is that the displaced water can only go in one direction. It'd be a pretty coincedental impact for a meteor to hit somewhere where that can happen.