Lluis blogs about his recent work to integrate the Glade-3 GUI designer into MonoDevelop.
With his recent changes you can maintain your Glade-based UIs from within MonoDevelop: changing properties of widgets, manipulating your UI and the best bit is that whenever you add a new event handler it automatically adds the stub of code to the C# file.
You can see a screenshot in his post.
Posted on 15 Jan 2006