Digital Photography Review has an epic interview with Mr. Ichiro Kitao, General Manager of Panasonic's DSC Product Planning Group. DPReview asks some good (if gramatically malformed) questions, including "What's the reception been in the camcorder division been to the GH1?" (sic). In general I love DPReview and admire how they ask tough questions when they get these interviews, but there's one point on which I disagree with them:
We're not big fans of the dedicated movie button. Would it be possible to allow the main shutter release to optionally be used to stop and start movies?
No, but we will consider this option for the future.What happens if you press the shutter button when recording a movie?
It activates a one shot AF operation.
Panasonic's design sounds spot-on to me. Of course, I haven't used it, but the GH1's dedicated video start/stop button strikes me as preferable to having some kind of mode switch, and using the shutter button as push-to-focus seems ergonomically perfect to me.
Stills folks might be predisposed to place too much importance on the ergonomics of the video start/stop button. I guess if you're not planning on editing your video, you might want hairtrigger control over video recording—but I would much rather have my index finger hoving over something that is of use while I'm recording, like focus.
In stills, capturing "the decisive moment" is all that matters. In motion, precisely when you began recording is meaningless—but managing your dynamic composition during a take is everything.