I've thought of some of these independently. (It's good to see somebody else did too.) We could probably make more progress if we all kept a list like this publicly. Or even privately, with snippets shared where appropriate. I know if I went through some old journals I could scrounge up a decent list myself.

One I had:

Bash scripting in the style of hypercard.

Hypercard was described to me as a system that had a set of functions and let the user make programs out of them. Bash syntax is simple enough that making an interface that gives you the power of shell without degenerating from the original should be possible. The output should be a regular text based bash script, allowing others to edit without the program and the user to see what's going on underneath.

EDIT: A second idea to go with the first:

A utility that allows you to create a GUI window from the command line. This could be used in conjunction with the Bash script editor to make graphical programs that the user can easily incorporate into their (presumably window based) workflow.