We're currently working on a developer's guide which will hopefully fill some of the gaps you mention. Here's a compendium of useful links for getting started (I'm sure you've already found some of these):
Architectural Overview: http://opensource.adobe.com/wiki/display/osmf/Strobe+Architectural+Overview
Intro to Traits (PDF): http://opensource.adobe.com/wiki/download/attachments/34373769/traits+intro.pdf?version=1
Features & Roadmap: http://opensource.adobe.com/wiki/display/osmf/Features
Building a HelloWorld app with OSMF: http://blogs.adobe.com/osmf/2009/09/building_a_helloworld_app_with_osmf.html
Intro to OSMF (video from MAX session): http://2009.max.adobe.com/online/session/332
Technical Intro to OSMF: http://blogs.adobe.com/osmf/2009/08/technical_intro_to_osmf.html
Intro to OSMF (by Jodie O'Rourke): http://jodieorourke.com/view.php?id=111&blog=news
If you'd rather see running code, the most succinct app for seeing what OSMF can do is the ExamplePlayer (source is here). It shows a wide variety of examples, each of which is represented by the exact same base class (MediaElement), which is what allows the player code to be decoupled from the various media implementations.
If you make it through all of the above :-), I'd be curious to know a) whether they're helpful and b) what's missing to help you get started.
Awesome, thanks. I have myself to blame for missing the links in the wiki. After more digging I found this page, which has some of the info I was looking for: