So this may be old news to most of you, but I thought I'd post it anyways. I'm sure we've all seen how amazing the Mark II looks when shooting video, and have heard/experienced (I haven't experienced, but I know some of you have) that the Mark II lacks some essential manual user controls when shooting video. Luckily, some hard working developers are putting together a new "open platform" firmware update that moves the Mark II ever closer to being a truly unstoppable cinematography tool.
The platform is known as Magic Lantern (Link) and is dedicated solely to improving the Canon 5D Mark II. Their first effort attempts to make right specific wrongs such as: Adding on screen Audio Meters, Disabling Auto Gain Control (which in turn enables Manual Gain Control), the addition of Zebra stripes display, and crop marks for widescreen, anamorphic, and standard 4:3.
These initial enhancements are what appears to be only the first phase of a quite ambitious ToDo List, which includes features like; variable frame rates, 720p recording, better metadata recording, and the ability to manually select Aperture and Shutter settings while the camera auto adjusts the ISO for proper exposure.
The bad news: The firmware isn't available for mass distribution yet, and there seems to be no sign of when it will be ready. Regardless, the Canon 5D Mark II has the potential to be quite a revolutionary camera, assuming communities like Magic Lantern continue to push the technology further and further.