It?! Is it possible?
Yes, you can with a product called "Hydra" from RemObjects:
http://www.remobjects.com/hydra.aspx
They have a demo showing the inclusion of a WPF graph in a Win32 application.
As Ken White points out, you can develop all your .Net stuff in Delphi Prism. It can then be used in Win32 with Hydra if you want.
You can look at the TMS.NET Interop Tools Pack . It contains components for displaying xaml and xps files in your delphi application. How well this works - and if it works well enough to switch from vcl to xaml, I don't know ...
Not. Delphi 2009 does not support .NET at all, and Delphi 2007 does not support version 3.x of the .NET platform. However, you can use WPF with Delphi Prism.