When trying to grok a new technology, it’s sometimes useful to look behind the curtain and seperate out the moving pieces. Someimtes this lets you get a handle on scope and lets you focus on individual pieces of the whole stack.
With SharePoint Framework this is no exception. To my eye, it looks like this right now:
I’ve also shared a slide deck here: http://www.slideshare.net/SeanMcLellan2/sharepoint-framework-developer-preview