Something that the Magic Kingdom has lost over time is its sense of kinetic energy. Things like the keel boats, canoes, and the sky way (in addition to various fountains that have disappeared as well) added a great deal of energy that is now lacking :\ They added more than just "another attraction"... they made it feel more alive.
It would be great to see the keel boats (or canoes) make a comeback. They still have keel boats at Disneyland Paris (although they are seasonal... but so are the riverboats since the river can freeze solid in the winter LOL) so I can't imagine it is something they could bring back if they wanted to... I don't know the story of the accident but I would think if there was a safety concern there would be a way to address it. And obviously they still have the canoes at Disneyland.