I think it would make an excellent backend for a visual programming language. I've developed a simple data flow-based system that I use for home automation, and could see using something like this to replace my current "interpreter." Imagine something like Yahoo Pipes or Pure Data compiled directly into parallel code.
Granted, tasks which have a natural sequence can be a lot more difficult in dataflow-driven languages, so use whatever works for a given situation.
Actually, that is something we've discussed on the mailing list (I've been on the list since the last time this was posted to HN) and its something I'm personally interested in building once the compiler and runtime are far enough along. Dataflow-based visual programming is something I've been very interested for a while now and is even partially related to my startup stuff, so its something close to my heart.
Granted, tasks which have a natural sequence can be a lot more difficult in dataflow-driven languages, so use whatever works for a given situation.