We've cross a few authors that were writing books for O’Reilly with IPython Notebooks in the last few month and we have plan to help convert those to (and from) many format. We would be extremely happy to work with people from O'Reilly to simplify the conversion process.
We also have plan to integrate with publication in academic world (see https://github.com/ipython/ipython/issues/4119) but we really need more people involved than the few of us (Core Team).
Even if IPython seem like a big complicated project, moving forward in area like document conversion is not that hard, but just needs lots of eyes and tester to catch all cases.
As for people wanting to convert notebook to other format than those currently supported, it is perfectly possible using nbconvert with template. We can spit the TeX that is just between begin/end document so you can include in your preferred dissertation template. It should be pretty easy to also just write a converter that export to asciidoc or doocbook.
For those interested of the idea behing how nbconvert I wrote this quite some time ago: http://nbviewer.ipython.org/urls/raw.github.com/Carreau/post... and https://github.com/ipython/ipython-in-depth Offer some example too.
Hope this will push some people to contribute, we'll always be happy do guide you in your first step.