I would like to keep firefox as my system default browser on my Mac, but launch IPython Notebook in Chrome[1].
This answer led me to my ipython_notebook
Based on this answer, (running Python 2.7.3 and IPython-0.13.1 on Linux), all I had to set in my ipython_notebook_config.py
was
c.NotebookApp.browser = u'/usr/bin/google-chrome %s'
I'm guessing, setting c.NotebookApp.browser
to /Applications/Browsers/Chrome.app/Contents/MacOS/Google Chrome %s
should work for you.