Executing multiple controllers with one request

I'm designing an Ajax RPC Router for Rails using Ext JS library.

I need to dispatch actions to multiple controllers during a single

I made a piece of Rack Middleware and plugged it in to Rails
initializer in environment.rb

Rails::Initializer.run do |config|
    config.middleware.use MyRouter "rpc"

The following Rack Middleware is *far* from being complete. I show
dispatching to hard-coded controller/actions here as an example.

class MyRouter
  def initialize(app, rpc_path)
    @app = app
    @rpc_path = rpc_path

  def call(env)
    request_env = env.dup // <-- have to duplicate env for each
    if request_env["PATH_INFO"].match("^"+@rpc_path) # <-- detect rpc
      output = [] # <-- capture each controller's response into an
      ["company", "user"].each do |controller_name|
        request_env["PATH_INFO"] = "/#{controller_name}/load" # <--
re-write env
        request_env["REQUEST_URI"] = "/#{controller_name}/load"
        output << @app.call(request_env) # <-- Is it kosher to call
multiple controllers like this??
      [200, {"Content-Type" => "text/html"}, process_response(output)]

  def process_response(list)
      # iterate array of controller responses and return the body from

Is it OK to dispatch to multiple controllers like this?
In Merb, I implemented this RPC functionality using merb-parts.
Is there a similar/better way in Rails?

Ever get anywhere with this approach to dispatch actions to multiple
controllers during a single request?