It would be kind of a wiki but each update/edit is externally verified.
In science, each lab has several lab books where everybody documents everything they did. In the rare event of a patent discussion between two labs or unis the first entry in the lab book decides who gets the patent (it seems to be way more complicated than that by now). Usually these lab books are regulary counter signed by the supervisor to 'prevent' tampering but it's not a particularly secure system. Having the blockchain verify each entry's date and originality could be fun. (but I wonder how useful it would be in the real world - would patent lawyers take this up or just ignore it and say they're happy with the old system?)