The source code for the Silverlight 2 controls includes implementations for the following controls:
http://www.microsoft.com/downloads/details.aspx?FamilyID=EB83ED4C-AC85-4DE9-8395-285628EE2254&displaylang=en

- ButtonBase
- Button
- HyperlinkButton
- CheckBox
- RadioButton
- CheckBox
- ToogleButton
- RepeatButton
- RangeBase
- Slider
- ScrollBar
- ProgressBar
- Calendar
- DataGrid
- DatePicker
- GridSplitter
- TabControl
http://www.microsoft.com/downloads/details.aspx?FamilyID=EB83ED4C-AC85-4DE9-8395-285628EE2254&displaylang=en
