Good point – using modifiers to produce a motion may not create an actual movement of the target object’s center, which is what is tracked by the Track To constraint. In that case you’d have to use another method to transform the target.
I did some tests quite a while ago to check how a Cloth object reacts to gravity – at the time, I didn’t pay much attention to whether the Object was moving or just its verts. I’ll see if I can dig that up.
One way to get around this possible limitation is to use Vertex Parenting on the Track To target object. That way, if only the vertices move under modifier influence, the target will move with the parenting verts as well as with any object motion.
Here’s the basic idea: Some object is set in motion by using one of the forces or other modifiers. A vertex or set of three vertices is selected to act as a parent to the Track To target object (probably an Empty for this setup). The camera then follows the target object, which in turn is transformed by its parent vertices in the mesh under modifier influence.
EDIT: A quick test in 2.49b shows that a Cloth object falling through a Wind field does NOT have its object center diaplaced by either the Cloth sim reacting to gravity or the wind. So it seems you’ll have to use Vertex Parenting to have the camera follow the mesh deformations caused by the modifiers and fields/forces.
Further testing shows that camera tracking to a vertex-parented Empty works just fine.