Is it possible to build a good medium to full sized application using just silverlight as a host?

A few things that would be needed:
- dynamic pages (one silverlight "screen" can switch between screens, like a normal app.
- similar to a java applet which launches from the browser

I see that Telerik sells RadControls for WPF...but this is only useful (to me) if Silverlight can be a rich client platform through the web.