Windows 32bit Family XP RTM - 5.1.2600
XP SP1a - 1106
XP SP2 - 2180
Server 2003 RTM - 5.2.3790
Server 2003 SP1 - 1830
Server 2003 SP2 - 3959
Vista RTM - 6000.16386
Server 2008 Beta 3 - 6001.16510
Windows 64bit Family XP 64bit RTM - 5.2.3790.1830
XP 64bit SP2 - 3959
Server 2003 64bit RTM - 5.2.3790.1830
Server 2003 64bit SP2 - 3959
Vista 64bit RTM - 6000.16386
Server 2008 64bit Beta 3 - 6001.16510
Chris Bowen, a Developer Evangelist for Microsoft has compiled a list of Silverlight 1.0 & 1.1 games that are currently available, each (but one) with source:
"Dr. Popper" [source] - Burst the matching bubbles, the more, the better.
"Digger" [source] - Sort of Dig-Dug meets Montezuma's Revenge.
"Zero Gravity" [no source available yet] - An addictive and well-made game! A nice example of the possibilities of the platform.
"Chess" [source] - Your basic chess, but shows how Silverlight 1.1 with .NET fares against a JavaScript-based AI.
"Sprawl" [source] - A good demonstration of potential with Silverlight 1.0.
"Destroy All Invaders" [source] - A cool mashup with Virtual Earth where you fly over the oblique angle view of a location of your choice while shooting UFOs.
If you're interested in learning more about game development with Silverlight, Bill Reiss has been working on a great series of tutorial posts on his Silverlight Games 101 blog. Start reading from the bottom first, where he start with a basic game canvas, then adds sprites, a game loop, keyboard input, etc.