The dev part of Channel 9 have recently released their latest escapade - Windows Phone 7 toolkit. The Coding4Fun Windows Phone Toolkit is a set of Silverlight controls, converters, and helpers to make your life easier. They have put a lot of effort in building out the control set. Here is a list of controls they have provided:
A sample of the button styles.
You can download the code from codeplex at http://coding4fun.codeplex.com/