Zero Gravity game for Silverlight 1.1
The team at Terralever has put together a very polished game using Silverlight 1.1 called Zero Gravity. You can get more details at Tim Heuer's blog here:
http://timheuer.com/blog/archive/2007/06/26/zerogravity.aspx
It's really a great example of how designers and developers can work together on a project more closely that they have been able to work before, and some of the great results that can come out of it.