Because Sass's indentation schema is similar
to that of YAML and Python, many indentation-related
functions are similar to those in yaml-mode and python-mode.

To install, save this on your load path and add the following to
your .emacs file:

(require 'sass-mode)

sass-mode requires haml-mode, which can be found at http://github.com/nex3/haml-mode.