A while back I did a series of postings on the Silverlight developer experience (back when it was still Silverlight 1.1.) While I was able to get some basic features of a mapping app I wrote for WPF ported, I quickly ran into the limitations of the small control set of the early preview builds. Since then, I've been keeping an eye out for controls as public previews have been posted.
In the run-up to the MIX08 conference, these topics are going to be getting a lot of coverage, but in the meantime, I'd like to point out a couple control sets that I think are worth a good look.
ComponentOne's Sapphire toolkit (http://labs.componentone.com/sapphire) provide a really nice pallette of controls for building business applications. In addition to all the panels and widgets you'd expect, Sapphire offers some really nice chart and grid controls for your apps. For many developers I've spoken with, that makes all the difference when assessing Silverlight's suitablity as a business app platform.
InterSoft's WebAqua toolkit (http://webaqua.intersoftpt.com/) brings the look and feel of a popular user interface to Silverlight. For those who like those navigational metaphors, you now have a platform on which to add these to your apps without having to write lots of low-level code. I much prefer this approach to the more traditional models we've all seen for menus and folder browsing - I think you'll like them as well.
If all that's not enough, just you wait for MIX08...meanwhile, maybe it's time to revisit my porting exercise.