It’s not so simple to just make a class implement the INotifyPropertyChanged and create some properties.
Normally you have to REPRESENT a model. But how? Replicating the properties in the model that you want? Exposing the model itself using a property?
That is a good question that every MVVM lover should have asked himself when writhing a ViewModel.
You can take a look at this article. It really hits the nail on the head.
http://msdn.microsoft.com/en-us/magazine/ff798279.aspx
I normally expose the model directly and make UI classes that implement INotifyPropertyChanged. But I see the property mapping far more elegant and pure MVVMish 😉
What do you prefer?