This is a short test video we shot with the Canon 5DMkII fitted with a 20mm F2.8 lens and an Olympus E-P1 fitted with 20mm f1.7, 14-140mm zoom and 45mm f2.8 macro lens.
The Canon 20mm is a lens bought some 6 months ago. We used it on a Canon 500D for stills and video & have never used it on the 5DM2. Today we shot stills (of which more above) and video with it. It performed well for the video, though it would be a lens used sparingly. Its often a question of what to leave out with a wide angle lens.
We used the Olympus to see what its video performance was like, as we had never tried it out. The footage was a bit disappointing quality wise, with the exception of the 45mm leica panasonic lens. This lens likes this camera. We've noticed it on stills & its the same for video.
However overall the GF1 produces better video than the EP-1 and neither is a match for the GH1.
The nicest part of the day was actually getting out to use the cameras on a sunny, snow-free day. It felt like a jail-break!
D & B