I second the need for something like this. This kind of tool can be used for clearly communicating scope and even aid estimation of timelines because it shows all the complexity.
An IDE like this could be applicable to any multi-month project with sufficient requirements complexity.
I like this IDE from an engineer standpoint, but I think the killer app will be automatic report-outs. I wouldn't have to spend hours making status updates in powerpoint for every type of audience in the corporation.