From their Terms of Use, their entire section on refunds:
"Kickstarter does not offer refunds. A Project Creator is not required to grant a Backer’s request for a refund unless the Project Creator is unable or unwilling to fulfill the reward.
Project Creators are required to fulfill all rewards of their successful fundraising campaigns or refund any Backer whose reward they do not or cannot fulfill."
Except there are two problems with that,
1) These people don't have the funds to begin with, that is why they are running a Kickstarter campaign.
2) The actual contract language is that they "Backer" funds a "Project Creator" to attempt something rather than to deliver something.
So when you go to sue the person who has your money you have to contend with the fact that they have no money (and insufficient assets probably to get a lien against, and if they do they will just do the personal bankruptcy thing) and then you have to convince a court (or a jury) that they didn't try in good faith to deliver the project.
They will argue the Backers knew there was a risk when they started and that due to problems unforseen by the creators these risks actualized and there project failed to materialize. They will argue the Project Creator is just as harmed as the Backer. The only way you might get any money back is if you managed to prove fraud.
Kickstarter has only been around for a short while, so we have time to watch this unfold.
This is not 'new' (while Kickstarter is, crowd funding is not). I recommend you look up previous cases where the product wasn't delivered. There were a whole bunch in the 60's when a bunch of 'movie producers' were raising money to make movies. I took a cinema class at USC (it was a fun elective) where the professor claimed that a lot of the contract language that exists today for production companies came out of the lawsuits of that time.