I wrote this in early January 2012, but never finished it. The research and thinking in this area led to a lot of the design of Yeoman and talks like "Javascript Development Workflow of 2013", "Web Application Development Workflow" and "App development stack for JS developers" (surpisingly little overlap in those talks, btw).
Now it's June 2013 and the state of web app tooling has matured quite a bit. But here's a snapshot of the story from 18 months ago, even if a little ugly and incomplete. :p
- Intro to tooling