The model binding infrastructure within the ASP.NET MVC
Release Candidate has been refactored to add additional extensibility points to
enable custom binding and validation schemes. You can read more about
these details in the ASP.NET MVC RC release notes.
Model Binders can also now be registered for interfaces in
addition to classes.
IDataErrorInfo Support
The default model binder with ASP.NET MVC now supports
classes that implement the IDataErrorInfo interface. This enables a
common approach to raise validation error messages in a way that can be shared
across Windows Forms, WPF and now ASP.NET MVC applications.