Most of the large control suite vendors have already started releasing their offerings for the Silverlight platform. One of those, namely divelements, has put together a couple of samples on what you can do with their controls. So if you are interested in building line of business applications in Silverlight such as an mail client, word processing, or something similar, check out http://divelements.co.uk/silverlight/.
Furthermore divelements is offering a free set of simple but commonly-requested tools, including an HTML display control. This control allows you to embed HTML anywhere in a Silverlight application by simply specifying raw HTML to display or, if you prefer, the URL to a web page.
The control works by asking the host browser to create a DIV tag in which to display the HTML, and positioning it cleverly to match up with the Silverlight layout system. You should find that this “just works” as the HtmlHost control is dynamically moved or shown (on a tab page, for example) or even if the Silverlight plugin itself is moved. You must be using the Silverlight plugin in windowless mode to use this control