I would like to be able to connect different shapes (rectangles, rhombuses/diamonds, ellipses, but potentially everything). The connector line should either be solid, dashed or dotted and end in an arrow. If I move a shape, both of the connected shapes stay connected (the line expands/contracts as necessary). The line should be able to carry a text label, either in the middle, at the beginning or the end (supercool would be if you could add an offset from/to beginning/end of the line).

In other words: I would like to be able to draw a flowchart.

For me as a UX designer (not doing visual design at all!), this is a very important feature to think about interactions on a high-level (which screens/states are there, how are they connected, how does a user move through these screens). Right now, I still have to use Axure for that job, or a dedicated diagramming software like OmniGraffle or (in the old ages) Visio.

This feature could be supported in Design Mode. It's not meant to span several artboards. In fact, for such a feature I would only need one (large artboard), or even better an infinite canvas. As an alternative, it could get a dedicated mode, like a "Flowchart Mode".

Also, in large projects I had to draw more than one flow chart. As an example, last year I had to draw a really large one (needed to be plotted on A1 paper to discuss with clients), but in addition to that, I drew ten sub-flowcharts (the large one was the high-level, the smaller sub-diagrams showed what happened when a user entered a specific screen). All those flow charts were printed into one PDF file with eleven pages. With Axure no big deal – with XD impossible. :-(

Thus, it would be cool to be able to draw one flow chart. Then, add more features like the support of more than one flowchart and the abbility to export only a selected one or all of them into one PDF file. Add more features over time to further improve that, like the different positions of the text label on connecting lines.