I’ve been noticing that VS 2008 was crashing a lot for me since installing the Silverlight 2 VS 2008 Tools.  It seems that Cider is freaking out but Jon Galloway came to my rescue.  If you’re experiencing the crashes, go to:

Tools->Options->Text Editors->XAML->Misc->Default View

Check “Always Open in docs in full XAML view”.

I would have preferred to just get the XAML.xsd from MS but since its not in the SDK, we have to use the XAML editor (instead of the XML editor) to get intellisense.