Having spent some more time playing with Silverlight (both 1.0 and 1.1) lately, one of the things that's noticeable is that while you can create pretty much anything you can imagine, particularly using Expression Blend, the current crop of built-in controls is somewhat limited. While that's not surprising in a newer technology, it may leave some wanting more...thankfully, as Silverlight geek Pete Brown notes, folks like ComponentOne are happy to help:
ComponentOne "Sapphire" is a set of UI controls for Silverlight 1.1. The animations on some (especially the hyperpanel) still need work, but overall, this is a really nice and complete set of controls. They even include a number of the missing panel controls. I would expect a number of these controls will be redundent when the final SL 1.1 release comes out, but choice is usually a good thing.
BTW, be sure to check out the rest of Pete's blog, too. In addition to good Silverlight stuff (such as this fun Beatbox app with Silverlight and ASP.NET AJAX), he's also got interesting notes on his carpentry projects (well, interesting to me at least, since I also do carpentry as a hobby)