Hi folks,
the batman-adv gateway support has left the experimental stage and will show up in one of the following releases (probably early 2011). To make this feature a really useful one I wrote a wiki article to explain how it works and how it is supposed to be used: http://www.open-mesh.org/wiki/batman-adv-gateways
Feel free to demand clarification if the text is not comprehensible. ;-)
Regards, Marek