Voxeo has just announced the Voxeo Designer 8, a new call control designer for their hosted platform.
I haven't used Designer 8, but other similar tools include ThinkEngine's CallFlowDesigner, Telephony2 CallButler (which integrates such a tool), and Angel.com. The pioneers in this space were Pronexus with their VBVoice. All allow scripts to be created, graphically, which can then be used to drive a call processing engine.
The reason these applications are so important is twofold: one is time to market. they speed the development of telephony applications. The second, however, is that they increase the volume of innovations. That's because these applications allow more developers to more easily write telephony applications without having to understand the nicky-norks of IVR programming.
Three years ago the only folks I was aware of in this space were Pronexus. It's a very good sign that so many companies are now delivering these kinds of tools. If you think back to the early 1990's, it was the emergence of tools like Visual Basic and Delphi that led to the explosion of IT applications on Windows. A similar, widely deployed graphical tool for telephony development could lead to the same accelerated pace of innovation in telephony.