When purchased my Canon 5DMkII I was I was naive about video. I didn't realize that when shooting video in LiveView autofocus is disabled so you have to focus manually. Woa, big surprise and what a challenge.
Luckily, when shooting most real estate subjects you're using a wide angle lens with a lot of depth of field so you don't need to worry that much about focus.
However, focus becomes a major challenge if you are shooting an person where you want to take advantage of the ability to shoot wide open with a lens that has a nice bokeh so the background is out of focus and the person is in focus. When shooting stills this is a piece of cake? When shooting video where autofocus is disabled focus becomes a world class challenge!
After going through this focus struggle with my 5DMkII my attention was grabbed when I recently noticed the Nikon D7000 specs say that, "the D7000 can maintain AF during live view and movie shooting, thanks to its AF-F ('full time') AF mode". Wow, where do I sign up? Oh, except all my Canon Lenses don't work on the D7000. On second thought, maybe Canon can change the microcode in the 5D so autofocus works in LiveView. I have no idea how good this full time autofocus mode works on the D7000 but it sure sounds good to me!
I thought I'd bring this issue up since there may be others out there used to shooting stills that have no idea that autofocus goes a way on most current DLSRs when they start shooting video. But it looks like that is starting to change! Thanks Nikon.
Update: Nov 6, 2010. Robert Barr sent me this test video of his new Nikon D7000 to show us the quality. Unfortunately this doesn't demonstrate the new AF-F full time auto focus mode.