HI,
The ability to shoot HD video was a major reason to purchase the 7D, along with its high ISO abilities. However since it has arrived, I have had very little time to explore its potential. I shot these clips by clicking the switch over to video, starting it and stopping it. I have not looked at tweaking the settings.
These clips of Twite were taken in mediocre light (overcast) but I am really pleased with them. I have 'cropped' them using iMovie on my Apple iMac, they were shot using a 300mm f2.8 lens and a 2x teleconverter
http://www.vimeo.com/9639019
http://www.vimeo.com/9628632
I promise to do my homework on the video section of the manual before I try again!
Mícheál