Ted Patrick has release DARE – The Adobe AIR Development Web Server that he has been working on. Currently Mac only the website says:
DARE is a local http server that makes it easy to create, test, and package AIR applications. It allows you to develop and test using your HTML/JS tools of choice and just a web browser. You can even use the “Refresh” button to test and package your application.
This should reduce the learning curve of existing HTML developers getting into AIR development.