I'd like to try the plugin for Vim linked below. It adds syntax highlighting for .haml and (perhaps) .sass files.
http://github.com/tpope/vim-haml
I did this...
$ cd ~/.vim
$ git clone git://github.com/tpope/vim-haml.git
I opened a .haml file in Vim, but there's no highlighting. There must be another step I need to perform.