It would be fun to be able to write a GUI, wish I knew how.
One thing I like about the Mitsubishi display is a coordinate display for "Next" moves for all axis. That is the cat's ass. It gives you the incremental distance of the move after the present one, and it isn't changing so fast that it is meaningless. Besides, when single stepping through the program (on a lathe job) you can darn soon decide "hey, I don't want to go that far!"
Knowing that the display updates are rather slow when running Camsoft, I don't know if Distance to go would live up to your expectations. As Karl suggested, it might be possible to rig up a "Next" display in the form of a set of labels that might look like a poor man's digital display. You'd have to write the logic somewhere (in the G01 and G00 logic) to compute the label contents from your gcode.....I'm not sure how much that might bog down the PC when running short segment gcode.
Edit: just thinking about this, I am not sure exactly how you would 'read ahead' one line of gcode in Camsoft, so that you could grab the coordinates and do a difference operation between the current move and the next move.
First you get good, then you get fast. Then grouchiness sets in.
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)