Would the lens mount on the 7D be able to support the 70-200 2.8 IS II without mounting the tripod collar to the rig? The reason I'm asking is because I plan on quickly changing lenses while shooting and want to make sure I don't damage the lens mount.

I'm pretty certain that lens has to be mounted on the tripod by its collar. That's why I got the 70-200 F4. It's much lighter and can be changed as quickly as any other lens. I use the lens either outdoors or for interviews where lighting is no problem, so the f4 is fine.

I'm now testing as I write this a canon 70-200 EF L lens on my 7D and I think, if you don't do something rough, you use a rod system, use a tripod, your ok not using the collar.

I often use a nikon 80-200 as well and i dont use the collar, however i "rest" the front end inside the mattebox.

The nikon 80-200 and canon70-200 weigh the same. Not sure about the canon IS II version.

Good idea--use a rods system with the lens support that most have as an attachment. Then you can get by without using the collar for mounting.

The 70-200 IS is about 3.5 pounds, I think, twice the weight of the f4 version and heavier than the camera.

The best way to handle larger/heavier lenses that you need to have the ability to quickly mount and un-mount is to use a quick release clamp and quick release plate

this is one for the 70-200 lens...

Really Right Stuff - L84: Used with various collared lenses (http://reallyrightstuff.com/rrs/Itemdesc.asp?ic=L84&eq=B86-006&Tp=)

Brandon,
I have the 70-0200 2,8 is, and I don't feel comfortable using it without addditional support. Up till now, I use it with either a rail set up, or with the collar on a tripod or monopod. it's just too heavy to let it hang off the 7d with no support.
I like the idea of the f4 version because it weighs so much less. And most of the time I'm shooting at at least f4.

When I use the 2.8 with my rail system, I still use a support bracket towards the middle of the lens. This is a pain because I don't use the support for the lighter lenses. So to put the 2.8 on the raisl, I have to first take off the follow focus to be able to then slide the bracket on. It's extra time.

If you're going totally hand held, then you can get away with the 2.8 and camera only ( just like you were shooting photos), but I still support it with a hand under the lens.
Bruce Yarock

Likewise - after handling the F2.8 I chose the F4 - almost entirely based on the weight factor ... not the cost.

I would not use the F2.8 without support - though I do have rails and lens support attached, I still went with the F4 mainly because I want to put the 7D on a rig.

I often use a nikon 80-200 as well and i dont use the collar, however i "rest" the front end inside the mattebox.

This is how my 70-200 rest its front-end inside the mattebox, in addition to resting on the follow-focus gear, i.e. I'm using no tripod collar: My Camera -- manhandled by Jessica on Vimeo

-- peer