I have a window that has a lot of content. I\'d like to be able to separate the content using panels, and have a separator that the user can click on the toggle between each
I think what you are looking for is an "Accordion" control, here is a post abotu how to build one from a stack of Expander controls:
http://www.rooijakkers.net/Blog/post/2007/11/WPF-implementation-of-a-basic-Accordion-control.aspx
And for the animation take a look at the "Reveal" control from Kevin's bag-o-tricks at http://j832.com/bagotricks/
I think there's even an animated Expander control template based on the Reveal control in the sample project.