If you have read previous blog posts you will have seen the problems that I have encountered viewing and editing the HD video from the Canon 5D Mark II on a PC. Due to the files being Apple Quicktime MOV format there appears to be no issue using them on an Apple Mac but due to the need to decode on a PC they do not play smoothly.
I have now discovered some software called Cineform NeoScene which enables the MOV files to be converted to native AVI files that both play and can be edited without problems on a PC. The conversion process is very fast and allows both single file and batch conversions.
Although not cheap at $130 this appears to be the perfect solution for being able to edit video from the 5D2 on a PC.