Douche disclosure occurs when you have coordinated a vulnerability disclosure with a vendor. The vendors agree on a patch release date. Then you, the researcher, begin talking about the vulnerability in the media weeks before the patch date. You get extra douche points for naming the vulnerability, creating a logo, and publicizing this. For maximum douche points, you ensure that the name of the vulnerability points other researchers to the location of the bug in the underlying protocol, weeks before patch release.
Metzmacher really stepped in it with his douche disclosure of the Badlock vulnerability.