WPF for the web = Silverlight or XBAP
In other words, you convert your application to Silverlight or deploy it as an XBAP (XAML browser application). Of course this requires quite a lot from the user's browser, in terms of plugins etc.
Another option would be to render a bitmap image from the WPF, and show that on the page.
http://www.codeproject.com/KB/WPF/WPF-Image-to-WebPage.aspx