I found the breakdown between customer and problem hypothesis very interesting. I'm currently working on a tool to store ideas(blatant self promotion:
http://www.255ideas.com). I was very interested in the customer/problem/solution hypothesis model. I think having directed fields may help guide the user in writing down their idea. But I also have to wonder, does it force the idea into a structure that it wouldn't take otherwise? Perhaps it would filter ideas that aren't focused on creating on solving a problem. Awesome ideas might not make the cut, for example, draw something.
IMO the most effective way to show an idea is with a prototype. It's also the hardest.
I also like the ability to add assumptions that are validated/invalidated. The focus on business plan is very cool.
Thanks for the link.