Martin Zwilling has posted this article which outlines six areas of uncertainty to resolve before jumping into a startup:
- There are few competitors in your target market
- There are no patents in the way
- There's a large and growing market
- There's real customer pain and customers who have money
- The complete solution can be delivered and not depend on something that's not there
- You have a motivated and qualified team at hand
These are good starting points for Hypothesis Driven Development, although, as I pointed out in that article, every person and idea combination will have a different set of concerns.
This particular set of concerns says more about the personal experiences of the author than about what questions you, personally, should be asking about your startup. Chances are, every one of the six points above relates to something which killed or almost killed one of the author's past ventures.
There are more generic ways to drive the discovery of your initial hypotheses... more on this later.