over at ipython/nbconvert#13, @Krastanov requested the ability to re-run all cells in a notebook before doing a conversion.
@Krastanov said:

Is there a way to evaluate all cells of a notebook before we use nbconvert?

Why:
I am writing a script that will convert our example notebooks to some static form to be part of the documentation. But many of > the examples contain plots, which take too much space to be kept in git so we are keeping only the unevaluated notebooks in the tree. However we want to generate documentation containing these images, so we must generate them somehow?

I suggested this can legitimately live in the ipython notebook entry point (hence this enhancement request), but can also see the advantages of having that functionality in the (forthcoming) ipython nbconvert

This would be the equivalent of clicking on "Run All" under the "Cell" menu of a notebook and saving it, without needing a web browser.

This is somewhat similar to, but different from #945.