We\'re just getting into MVVM in WPF.
We have implemented our ViewModels with \'strongly typed\' properties (int, double? etc.) that we bind to in the view.
Type
Absolutely it belongs in the view model, for all the usual reasons, including:
On the other hand, conversion, validation etc. will be less declarative, explicit and flexible, from the point of view of the View designer
I think this is a moot point because the view designer should be responsible for these things. The designer is trying to make the UI look and feel a certain way; it is the developer who implements the business logic, including conversion and validation logic.