zoom controller for gh1 ?
 

Looks like the solution to zoom control might be something like this

Canon | FZC100 Flexible Zoom Controller | 1824A021AA | B&H Photo

or maybe someone will design a followfocus/manualzoom unit together - heads up Redrock !
There are also very expensive servo/motorized external units costing double the price of the gh1 . And there were alot of these for 16mm lenses that might be adapted . I , for one , like a manual zoom if it can be controlled thru the full range.