Yes, the camcorders are less money, but the 5D mark II has a DOUBLE-sized frame compared to 35mm motion picture cameras, which are shooting to half of a 35mm frame...that alone seems to make the independent videographers and the Directors of Photography totally salivate for the Canon,turned into a small, 7-pound DOUBLE-frame 35mm camera capable of extremely shallow DOF effects....plus Canon d-slr's can utilize almost any lens from some of the best-ever lens systems--Leica R, Canon EF, Nikon F-mount, Olympus OM, to name the most prominent lenses.
Right now, some of the independent video directors around the world are moving to the Canon 5D for that gigantic, double-35mm-motion-picture sized frame and the ability to use, relatively speaking "affordable" Canon and Nikon and Zeiss 35mm still lenses, which cost less than the dedicated motion picture lenses.
I was surprised at how good d-slr video is; I saw a nice Nikon D3s rap video on YouTube last week,and it looked good. The absolutely HUGE sensor in the 5D-II, combined with its high ISO capabiliy, is giving world-renowed videographers like Philip Bloom a major 'woody', and he and others are staerting to think about candle-light video shot at ISO 800 as perfectly capable...the much smaller vikdeo camera models do not have "quite" the same capabilities in either format size, depth of field control, or ISO (gain). So, guys like Bloom are really starting to take to the 5D-II.
This season, NBC shot the opening sequences for Saturday Night Live with Canon d-slr's, and even did an entire commercial parody using Canon d-slr video (Bladderol, I think it was) for the season's first episode. Also, according to pop photo and some lens industry insiders, the insiders think that the in-body stabilization PLUS in-lens stabilizers might be able to be paired and used simultaneously, for ridiculously slow-speed video shooting under truly extreme situations.
Right now, from what I have read, videographers at ALL levels--independent, staff, TV network, and Hollywood motion picture production company levels are snapping up 5D-II's and going nuts on them--as an alternative not to small 3-CCD videocams, but as supplements to mega-cameras. It seems like we're just getting started right now with d-slr video--it's only been on the market what? A year now?
Review: Learn Canon 5D Mark II Cinematography with Philip Bloom DVD at DVInfo.net
Bloom started using the 5D-II, worldwide, within a month of getting his, on paying jobs. Apparently, he's not alone either.