It have not benecesary a replacement for the current event sheet editor. It would be a tree style event sheet navigator or viewer. I think that the current system is very usefull, but when the projects are becoming biggers, it would be usefull to have a quick preview of the general "flow" of the project. And here you would select an event and highlight it in the current editor; basically, an explorer.
Thomas: Yes, definetly Fusion is awesome. I think is like comparing After Effects and Fusion interfaces. For quick and "simple" composition, I am more comfortable with After Effects. It is based in layer concept. So, when you are making more and more layers and precompositions, it becomes a chaos. For larger projects with more people, Fusion is cleaner and more "readable". After Effect works in a linear mode, but it have too a node based explorer, not editor.
dkdoom: I know this software. But this program is two "low level" node editor, I think. But a good reference.
Interesting link to see Fusion interface in action: http://www.eyeonline.com/Web/EyeonWeb/marketing/21reasons/21reasons_3.aspx