I noticed a post in the discussions area on CodePlex this morning called Show Scrollbar when View is to large . I had a look and thought I would have a go at coding that since I remembered the different controls in the book WPF 4 Unleashed that I recently read.
Earlier tonight I posted a idea of what might work based on testing with WPF only. Since then I've created a basic version using Caliburn Micro. Both are only small demo's so please don't be too hard on my coding. I've not been able to do as much as I would have preferred for a while so I will be a bit rough around the edges. That and I'm still quite new to WPF and MVVM.
Both zips should contain everything needed to run. Feel free to comment if you have any troubles.