Yeah. @faeran and I have to draw straws at some point before release to see who the lucky soul is that gets to update the theme documentation with all the new bindings and converters....
Essentially those bindings are for the individual items that are displayed in details. You now have a binding for the full string, a binding for the value, and a binding for the visibility of each item that can be displayed in filter, platform, or game details views. This way theme devs can now render those details outside of the details view, or rearrange that view however they see fit.