It's an accessory that PocketWizard is making.


It'll go on sale October 2009. Nope,


It'll go on sale December 2009. Nope,


It'll go on sale March 2009. Maybe.


http://www.pocketwizard.com/news_events/news/dec_updates/


[Edit: Oops, should have added for clarity here: it's an accessory that sits on the on-camera Mini/Flex and manages the E-TTL or manual flash balance for remote-adjustable flash units.]