I have an problem with tradional unix text-editors--vim and emacs for example--and I'd like not to have that problem with future text editors you or others may create.
The crux of this problem comes down to navigation and newlines. Traditional unix text editors understand a new line as ending when the newline character appears. This means a line can span many 'rows' on the screen. This makes sense because this is how lines are represented internally. But unless you think this way--and you wouldn't unless you habitually think in low level computer representation and don't often use saner text editors--navigation in such text-editors is quite un-natural.
For example, let's say you're reading back some text you've written and find you want to change something. Your initial reaction is to navigate to that error from where you are at the moment. So, you find where the cursor is located and say something like, "five lines up and a bit to the left." But you can't directly do this with the arrow keys or key shortcuts, because you're thinking about lines in a fundamentally different way to such a text-editor.
In everyday life we navigate objects visually. We should be able to navigate the cursor in text-editors in the same way. And so I implore the developers of future text-editors to make the default navigation behaviour to understand lines as how they are visually represented, not how they are internally represented. Please.