I recently posted a comment on a discussion whose topic was similar to the above; the the initial question was related to the very high failure rate of IT projects.
Most of my experience refers to IT product development, so I'm not talking about other things such as insuring an IT project against political instability. As other contributors have pointed out, insurance companies will consider all the risks involved, which means that with such a low success rate software projects are not so likely to be insured, at least as a rule of thumb.
Most of the times the problem lies in the process used to manage the projects, so a better process - which can result in a more motivated team - is often the best insurance you can get.
More on this on this great book by Craig Larman.