Having played with it a week the 7D isn't a camcorder
The big thing to understand is there's NO autofocus (I was aware of this before buying) this means you need to stare at a 3" LCD while holding the camera with right hand and twisting the focus ring with left hand to keep subject in focus
This setup is pretty unstable for hand holding video, that's why if your serious you'll need an eye glass etc to help stablise the camera, look up zacuto z finder to see what I mean.
The big deal though is being able to get DOF effects in video, it's like comparing a cheap compact to a DSLR, current camcorders are blown out of the water compared to what the 7D/5Dmkii can do in this regard, before the 5Dmkii launch you'd need 100k+ to get the same effect on film...
The other big issue is the HUGE files and editing requirements for 7D files, I'm sure it'll all sort out over the next few months but there's not a lot of support yet for the video side of things