Yes the Canon 5D MKII wins, but the iPhone 4S does almost as well with its new 1080p guts.
Here’s a “fair” test between the iPhone 4S and the Canon 5D MK II. I made a little rig that allowed me to shoot both cameras at the same time side by side. All scenes are perfectly synced together so you can pause and scrutinize the frames! See photo of the makeshift rig in the photo area.
Exposure, shutter speed, frame rate and picture style were matched as close as possible between the two cameras.
This test shows that the tiny F2.4 lens and sensor on the iPhone are pretty nice. It even got a little depth of field!
Also check an iPhone 4S video by professional film editor Benjamin Dowie after the click.