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.
This is a similar event in terms of a landslide sloshing into a body of water. Smaller in scale, but far more lives were lost.
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
From the BBC video: "They rode the wave as it swept them above the trees and washed them back into the bay."
Wow! I think I would be ready to move to the desert after experiencing something like that.
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.
Is it safe to assume that some meteor impact in the distant past must have had a taller wave, something measured in kilometres?
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.
So if this sort of thing has happened within living memory, it's probably fairly common.
Thera eruption was probably taller when it hit Crete.