What I'd like to see is interfaces like Live implemented in Pd.  Pd already has all of the audio tools, what it is missing is the GUI toolkit.  One of my goals with pd-devel and tkwidgets is first, to make some good widgets, and second, to make it easier for people to code intricate GUI widgets for Pd.

TkZinc would be a great base for such a thing, since it allows you to run the GUI code with OpenGL.