Should we mention the IPython 2.0 feature for exporting the notebook yet?

Edits of the rest of this text:

Nbviewer is based on `nbconvert` which is part of IPython. nbconvert is used to export `.ipynb` files to an increasing number of other formats. If you have IPython installed you can have access to the same functionality by invoking `ipython nbconvert` at a command line.