Despite having a very similar title, this is a rather different paper from http://arxiv.org/abs/1209.5145. We had to upload a version of this paper for a grant application, but it's still somewhat in progress.
This paper focusses on motivating the design of Julia for the larger scientific community. Any comments will be incredibly valuable in improving the quality of the paper.
Some ideas for improvements:
The package directory could be mentioned more prominently.
It's a bit tricky to select code in the PDF, not sure if much can be done about this?