Apple issued an update that brings iFrame video format support to the iMovie application available in the iLife '09 software package.
With the iMovie 8.0.5 update you can use the new iFrame format designed by Apple to speed up importing and editing by keeping the content in its native recorded format while editing.
According to this Apple Support article (Via 9to5Mac) the new iFrame format is based on industry standard technologies such as H.264 and AAC audio.
The iFrame format produces small file sizes and simplifies the process of working with Video recorded with your camera. iFrame is optimized for a resolution of 960x540px and 30fps.

The just announced new Sanyo VPC-HD2000A and VPC-FH1A are the first camcorders to support iFrame.