I have to admit I was sceptical about the video function of the 5D Mark II but after the new firmware its really a great feature. Went out with our niece and tried to put some video together. The quality (not talking about the content quality) is stunning on a HD TV unit in full resolution. My upload on Vimeo is a little smaller but it gives an impression. Shot with the 70-200 f/4 L. My tripod head sucks for panning so there is some room for improvement.
Warning: I'm not Steven Spielberg so don't expect to much
Make sure to watch it in HD.