What was the outcome of this? I am having the same issue.
Followed the Getting Started with... guide step-by-step up to the Apply Dynamic Dropdowns behaviors - Creating the Dynamic Array (the 4 steps Jason lists above, completed successfully). Following this step and clicking OK dosen't appear to do anything, no additional item is added to the Server Behavior list, thus Populate List from Array is grayed out in the Behaviors tab.
Dennis