Hi Jude, if you can do a series of manufacturer visits, manufacturing process of some of the flagship headphone, etc, that will be fabulous. Headfiers will appreciate much more how good their headphones are and it is also a way manufacturers can promote.
eg.This one tell us how the AKG K702 is made.
Video of gatherings/meetings will also be nice, as head-fi members are all over the world and probably most of us cannot attend but love to see what's going on.
my 1 cent.