Last Friday I had the opportunity to attend an Ash Maurya's workshop on Lean Startup, and finally had some time to spend reviewing his idea of the Lean Canvas (have a look at his original post on it for more details).
What I find interesting of his approach, and of Steve Blank lean startup method in general, is their systematic work to demystify the work and figure of the entrepreneur. We have so many books trying to describe famous (and less famous) entrepreneurs as mythological super-heros, but as Eric Ries and Paul Graham have noted, we don't know the real story behind successful startups, because nobody tells it on stage.
The Lean Canvas in particular can be seen as a tool to describe an initial startup idea (in term of the problem it is going to solve), and refine it iteratively using the scientific method (describe hypothesis -> experiment -> measure -> prove the hypothesis true or false). That's how the canvas look like
The Lean Canvas, in itself, is just a tool to describe the assumptions you make before starting your business; as such, it is useful, but nothing revolutionary, in my opinion. However it become much more interesting (and challenging) when you throw in some of the assumptions of lean startups:
Interesting enough, there's very little code during the development of the canvas (possibly only some HTML to layout a demo of the solution); it's all about finding the right problem and the right solution, and doing that in a systematic and repeatable way.