Good point! I will add it in the FAQ.
If you had prior art, but the USPTO misses it and still grants a patent, the fight is unfortunately expensive and time consuming, we wrote about that in our Legal Meetup blog post: http://www.oshwa.org/2013/12/05/open-hardware-legal-meetup-nyu-nov-11/
"After the time period has passed for public viewing of a pending application, the patent is awarded or denied. If a patent gets awarded, you will need to petition the USPTO to review any prior art that is in the public domain that the patent examiner did not know about : this costs $7K-17K in filing fees and attorney time. The process of petitioning the USPTO after a patent is awarded is expensive (think millions of dollars) even if you have prior art. At this point you’re in litigation, so call the EFF’s branch to Eliminate Stupid Patents."
Once we get enough donations to fulfill this project, we've been kicking around the idea of a prior art repository - however there is still no guarantee that the USPTO will use this as a resource - but we can hope!