Gizmox is an Israeli startup that developed an application UI framework that bridges good-old practices of building enterprise applications (using WinForms) with web 2.0 style application delivery (AJAX style). The idea behind their solution is that the WinForm application style can be sub classed to have a class that separates the UI implementation (and optimizes the communication between the UI and the application logic) from the UI logic. The result is that one can develop a Windows Forms style application and the WebGui class underneath emits an ASP.NET application that maintains states and connects a JavaScript based UI to the application UI logic that runs on the server. The result is a modern Web 2.0 style application that was developed with the Windows Forms UI paradigm. Note that the application is an ASP.NET application and can be extended in a standard way. The technology is licensed under an LGPL license and already in use by large enterprise customers (SAP is using it for their labs application).
Microsoft is holding a Webcast about this technology and I highly recommend registering and attending it.