How can I disable logging of asset pipeline (sprockets) messages in Ruby on Rails 3.1?

Sprockets tends to be quite verbose in the (dev) log by default under Ruby on Rails 3.1 (RC1):

Started GET "/assets/application.css" for 127.0.0.1 at 2011-06-10 17:30:45 -0400
Compiled app/assets/stylesheets/application.css.scss  (5ms)  (pid 6303)


Started GET "/assets/application.js" for 127.0.0.1 at 2011-06-10 17:30:45 -0400
Compiled app/assets/stylesheets/default.css.scss  (15ms)  (pid 6303)

...
Started GET "/assets/default/header_bg.gif" for 127.0.0.1 at 2011-06-10 17:30:45 -0400
Served asset /default/header_logo.gif - 304 Not Modified  (7ms)  (pid 6303)
Served asset /default/header_bg.gif - 304 Not Modified  (0ms)  (pid 6246)
Served asset /default/footer_bg.gif - 304 Not Modified  (49ms)  (pid 6236)
...

I'd like to either reduce the level of verbosity or disable it altogether.

I'm assuming there is a clean way to disable or reduce the verbosity of the logging by adding a config line in either environment.rb or development.rb similar to config.active_record.logger = nil which silences ActiveRecord SQL statements.

Place the following code in config/initializers/quiet_assets.rb

if Rails.env.development?
  Rails.application.assets.try(:logger=, Logger.new('/dev/null'))
  Rails::Rack::Logger.class_eval do
    def call_with_quiet_assets(env)
      previous_level = Rails.logger.level
      Rails.logger.level = Logger::ERROR if env['PATH_INFO'] =~ %r{^/assets/}
      call_without_quiet_assets(env)
    ensure
      Rails.logger.level = previous_level
    end
    alias_method_chain :call, :quiet_assets
  end
end

Updated: It now works for Ruby on Rails 3.2 too (previous attempt fixes before_dispatch, and now we're going for the root rack call instead)

Update: A proper Rack middleware solution (instead of fragile alias_method_chain) from @macournoyer https://github.com/rails/rails/issues/2639#issuecomment-6591735