One of the new controls I'm working on adding to the Physics Helper library for Silverlight, Blend and Farseer is a camera controller. You'll basically be able to just set a few properties on the camera control, such as the Physics Body to follow and the Zoom factor, and presto - the view will follow that physics body and smoothly zoom in and out.

The next iteration of the Physics Helper for Silverlight isn't quite ready, but I thought I'd share this fun little sample of the camera in use with a ragdoll! Note that you can use the mouse to manipulate the doll if he gets stuck.