Jem Schofield has posted a few greenscreen footage examples at The C47 that were shot with the Canon 5D Mark 2 and Canon 7D. I’ve not personally seen a lot of keyed footage from these VDSLRs, so this is good stuff. Not surprisingly, he recommends turning camera sharpening settings way down for best results. You can watch his video entry below, but if you have any interest at all in the topic you should definitely go read his blog entry for technical details and some full-resolution framegrabs.