This "format" isn't anything new to iMovie. It may be new to camcorder resolutions, but not iMovie. 960X540 has been the default "Large" video resolution for importing ANY video into iMovie for a long time now. This seems like a lot of smoke and mirrors to me. Like I said, this "format" has been in iMovie for a while. Apple has just managed to convince some manufacturer(s) to put this setting in their camcorders as the default recording format so that when you import the video into iMovie, it won't have to do any transcoding.
Here's more for you all. Even in Sanyo's press release on Reuters it talks about this new "format" using standards-based technologies:
"This new format can also be used with both Mac
and PC compatible applications due to the use of standards-based technologies
such as H.264, AAC, MP4 and MOV."
There you go, video codec, audio codec, and file containers. This is not a new format, but a repackaging of existing codecs and containers in a resolution that has been standard in iMovie since at least iMovie '08. It even says right in the article that this was done for ease of editing (read no transcoding). Rest of the article can be read at the following address:
http://www.reuters.com/article/pressRelease/idUS90873+13-Oct-2009+PRN20091013