So one of the new features in Silverlight 4 is that you can make controls ‘dropable’ which means that you can drag files from the local machine and drop them on controls in Silverlight and access these files. This can be handy in a mapping application if for example a user wants to add data in to the application and view it on the map. I just quickly created a simple video that demonstrate this:

Links:
Tim Heuer - Silverlight 4 Beta – A guide to the new features
Jesse Liberty - Using Silverlight As Drop Targets

ESRI will release Service Pack 1 for the ArcGIS 9.3.1 platform in December 2009.

More information:

http://geo.geek.nz/esri/arcgis-9-3-1-service-pack-1-coming-in-december/

http://downloads2.esri.com/support/documentation/ao_/9.3.1_SP1_Announcement9_1.pdf