If you're a member of the Adobe Enterprise Developer Program, then I think you'll find a helloworld-esque Photoshop hybrid extension in the PlugPlug Toolkit.
I'm a member of the Solution Partner Program - no any chance to have the PlugPlug Toolkit?
All the members are created equal, but some are more equal than others
Sorry for the delay, I had to ask around. Good news is, I'm told that all members are comrades
In the Extension Builder grouping you should see something called: Adobe Creative Suite 5 Extension Builder Native Application Toolkit 1.0.0 CS5