WPF is great and powerful technology to create compelling Windows Desktop applications when you need a rich user interface.
Artinsoft/Mobilize.NET provide tools and services that allows you to modernize your VB6, Windows Forms and Powebuilder apps to WPF. Once your applications are on WPF you can also benefit from features like XBAP...
"XAML Browser Applications (XBAP, pronounced "ex-bap") are Windows Presentation Foundation (.xbap) applications that are hosted and run inside a web browser such asFirefox or Internet Explorer. Hosted applications run in a partial trust sandbox environment and are not given full access to the computer's resources like opening a new network connection or saving a file to the computer disk and not all WPF functionality is available. The hosted environment is intended to protect the computer from malicious applications; however it can also run in full trust mode by the client changing the permission."
XBAP is in general a simplification of the Click Once deployment, but specifically for WPF applications.