I've recently produced and directed a history documentary about the Battle of Quebec in 1759 which is going out in the UK this Tuesday (16th March) on BBC 2. It was mainly shot with an EX1 but I used a GH1 as a B-camera, and quite a few of the GH1 shots made it into the finished programme.
It was great having it on location. I could use it to get extra footage whilst the cameraman was using the EX1. We also used it to shoot 2 camera sometimes eg for interviews. I was amazed how well the EX1 and GH1 footage intercut.
You can see a trailer here which includes a few GH1 shots.
A lot of the closeups (for instance of the musket and cannon) are GH1.
Panasonic GH1 & micro4/3 Community forum on Vimeo