[shalabhc]

> the nature of the visualisation required is very much an application dependent thing

I agree. Here gtoolkit is a recent example that's exploring the building of custom visualizations very easily. It's a compelling environment.

> Secondly, moving to a new programming language (or even a new development environment) is not something that most of us have the freedom to do in our daily work, and overcoming that inertia is a real challenge.

Couldn't agree more. But over time, things could change. Python was a small language a couple of decades ago.

> rather than looking for a panacea or a magic bullet, we can just try to use the tools that we have today to get as close as we can to the vision that so many of us share

Yes this is one way to move forward. The main issue I've seen is supporting 100% of Python becomes too hard since this idea is being retorfitted and the language/environment hasn't been designed with this from the start (consider getattr/setattr and IO). So certainly a large subset of Python (or another dynamic language) withing a custom environment could work as a starting point.