I’ve had a number of people ask me about intellisense with Silverlight 1.0 on VS 2008. The trick is to *not* use the WPF Editor (the one that won’t show Silverlight WPF anyway). To make it work:
Right click the XAML file in the solution and pick “Open With…”.
Pick “XML Editor”
Click “Set as Default” if you want it to always open XAML files in the XML Editor…