I agree that it is a good idea to send the newsletter to new community members but I still think that, for maximum reach (and therefore to further promote NS), a separate sign-up form would be a good idea.
After reviewing the first edition, I think there is a good mixture of technical and general information.
I not sure about actual actions that could be taken but this forum contains a friendly and vibrant community that provide some excellent work (on that note, I want congratulate @stephdl on his hard work and am really happy to see that his modules are being included within the core project 
).
NS highly encourages the input of community members (which I consider as a major strength of this open-source project) and I have enjoyed participating not only in conversations about specificly NS based issues but also more general discussions about the open-source movement and the history of Linux (I am thinking about the general discussions – re: topics including Office Web Projects, Remembering our origins GNU/Linux and What is your Linux distribution).
I do think if some of the more general topics are included within the newsletter, this would encourage more people to contribute to this forum (and the overall project). It would also be nice to highlight some of the work from participating users (if only to demonstrate that this is an active project and the fact that user input is being appreciated).