Yes its 2011 and Rails 3 has been out for a year but as far as I can tell, and many git reset --hard HEAD attempts later, haml requires the gem haml-rails to generate views. Even though Google may show results from 2010 they are still relevant. But haml --rails isn't what you want.
So Haml configuration in my Rails 3.0.9 project looks like (only relevant parts shown)...
#Gemfile ⋮ gem 'haml' group :development do gem 'haml-rails' ⋮ end
#./config/application.rb ⋮ module IlkContent class Application < Rails::Application ⋮ config.generators do |g| g.template_engine :haml ⋮ end end ⋮