You could take a look at the Smart Client Software Factory from Microsoft Patterns and practices; this provides quite a rich (but complex) framework for managing views within WinForms applications.
You may also want to look at one of the many third-party widows forms component vendors for some rich controls (Telerik, Infragistics etc).
CSLA is a good business object framework that supports winforms applications very well.
I currently work on a WinForms application built on the SCSF with CSLA; it's a steep learning curve but has produced a successful appllication wich the users like and is reasonably easy to maintain and enhance.