Juggaknot, you should watch a VR4 or S4 launch, they both have pretty soft suspensions and when they launch, they squat like crazy. (no tire squeal)
Body roll looks like that but just from side to side, if you take a hard left turn and you see the left side of the car, its wheel wells will appear to widen to something like SUV kind of clearances. The right side of the car will sort of squat and the tires may tuck into the wheel well some...
Now imagine this... you've got an LS400 and you jerk the wheel to the left goutn 40 mph... the car's suspension is 'soft' it tries to absorb as much hard cornering as it can... all the weight will shift onto the right front and right rear tires...
This is bad for cornering because when your corner you want the weight to be equally distributed across all your tires, that way you can increase the cornering limits of traction of all your tires evenly. When you have body roll, two of the tires will reach their traction limit before the other two, and become in a sense a bottleneck, since the other two tires aren't being put to their full potential.