I bought my JVC GZ-MG333HE at model GZ-MG335 which was reported to work on MacOsX and Imovie 08. They did not have it in stock and because the party was a few hours later I bought the GZ-MG333HE version. The salesman could not tell me if it would work on MacOSX.
There is not a lot of information on this camera, I even did not find it at the JVC Website. I figure because the shop advertises with lowest prices, vendors create specific models for these kind of shops too, not available in other shops. The information page at Vandeborre does contain some detail but it is still limited.
I was lucky, it just worked too! I connected the camera via USB and fired up Imovie '08. The harddisk was mounted in the finder and IMovie 08 found the camera and started generating the thumnails so that the movies could be imported.
The camera also has a still mode that allows you to take pictures. These pictures are easily imported by using Iphoto 08.
Metadata on Disk
Further analyzing the disk volume shows a directory structure:
./SD_VIDEO
./SD_VIDEO/MGR_INFO
./SD_VIDEO/PRG001 ---> this would contain the video files (MOD,MOI)
./PRIVATE
./PRIVATE/JVC
./PRIVATE/JVC/XML
./EXTMOV
./DCIM
./DCIM/100JVCSO ----> this would contain the image files (JPEG)
The private directory seems to contain some XML and XSLT files used internally by the camera.
./PRIVATE/SDVID.DAT
./PRIVATE/JVC/XML/PRG001.XML
./PRIVATE/JVC/SDVIDEO.XSD
./PRIVATE/JVC/MASTER.XML
./PRIVATE/JVC/SDV2MP7.XSL
./PRIVATE/JVC/MP7_2SDV.XSL
./PRIVATE/JVC/CAMEVENT.XML
./PRIVATE/JVC/CAMJEVNT.XML
./PRIVATE/DCFID.DAT
Info on the XML files found on http://www.jvc-victor.co.jp/schema/SDVideo SDVIDEO.XSD
Video Files
The JVC Digital Camcorder record videos to .MOD video format. Timestamps are recorded in small .MOI files.
These .MOD files a simply MPEG-2 formatted video, saved with the .MOD file extension. Simply renaming the extension from .MOD to .MPG. allows you to start your video player. The files don't seem to play with Quicktime but VLC worked fine.
A related page on information can be found at the apple discussion forum: http://discussions.apple.com/message.jspa?messageID=968758