MVVM is a topic that can easily take hours of discussion. Unfortunately, I only had less then one to talk about (at least some of) its goals, parts and possible implementations. Below is my slide deck:
And the code: download
The code is structured in a way that helps you see the changes in the code while progressing through the samples. Just follow the numbers (e.g. MainPage1, MainPage2, and so on). It’s mainly Silverlight code, with the last example being example of an easy transition to Windows Phone.
The sample application is a conference app that lets you see available sessions. I removed the online data endpoint so the online samples won’t work, but you’ll get the feel using the offline data provider. Speaking of data providers, there are three (online/Ntk, using OData endpoint, Offline (loads Xml file from resources), and Json (same as Ntk, just for getting data in Json format – you know, for the phone 
).
Once again, I have to stress out that code is for demo purposes only - while it’s minimized one end, it may be overly complicated on the other. Also, Silverlight Toolkit and JSON.NET libraries that were added through Nuget are not included in the zip.
Ah yes, the slides are in Slovenian language.