Windows Workflow Foundation 4 and ASP.NET MVC

We are evaluating Windows Workflow Foundation 4 to use in MVC 3 based Web Applications. We would like to create flexible order workflows for different projects.
Does anybody know good information about the general architecture or hands-on-labs for this kind of application?
Some concrete questions would be:

• how can you activate a specific controller/action from the workflow?
• what is the best way to communicate between the workflow and the web application (events, wcf services, ...)?

This is a nice article on how to start working with WF4 in your ASP.NET MVC app.

Integrating a persisted WF4.0 workflow with mvc