Before moving on with other things we may wish to extend, let’s upgrade the trivial addin from the previous post. Since we are integrating with Team Explorer, it would be great to know to which project we are currently connected. If we are aware of the current connection, we can hide the navigation item. Once we regain connection we simply show it again. Since this requires us that we update the UI, and as you’ve seen the UI requests data from us, you will see how MVVM is used in the navigation item to alert Team Explorer pane that something has changed in our UI.