I have a camera that I’m using to generate a top down orthographic view of the world to use as an overview map. What I would like it to look like is just black outlines of all the objects on a white background. I would prefer clean lines as opposed to blured lines found in most outline shaders. I came across this: http://wiki.unity3d.com/index.php?title=Silhouette-Outlined_Diffuse which mostly does what I need, but I wanted to apply the effect “globaly” through the camera and not have to put the shader on each object and I don’t know how I would toggle the effect by camera either. Probably somthing along the of this http://www.thecrosshouse.org/Page%208%20-%20Blueprints/Blueprint-First%20Floor.jpg but without the labels and such.
Note that some outlines shaders work on geometry (like your one) which means it has to be applied to every object, others work on screen-space, which means they are automatically applied on every object. So you might want to look for screen-space effect.
Otherwise you can look into replacement shaders (camera property) which allows to replace shader on all objects.