The Madison .NET User Group was very fortunate to have Al Pascual speak last night on Silverlight and GIS.  He had good demos and provided links to resources online that you should go check out.  Here is a link to his powerpoint presentation.

He currently works at ESRI and is working with mapping technologies and Silverlight.  Check out his blog and the presentation.

For those of us who have one of the HP tx2 tablets, we can already develop multi-touch apps for the Windows Phone 7 because the emulator supports multiple touch points.  However, I'm currently not able to get the Touch.FrameReported event to fire in a Silverlight app on the Windows Phone 7 emulator.  I'm hoping that it's just because this is the first rev of the emulator.  There are very few postings online that even talk about it.  I'm going to contact someone from Microsoft to get an official response on the subject.  I'll post the results as soon as I know more.