Vincent Vergonjeanne just posted BubbleFactory game written with Microsoft Silverlight 1.1 Alpha. You can play with it at http://cosmik.members.winisp.net/BubbleFactory/. And if you are really good at this game, you can get yourself in its scoreboard (top 10 scores).
Vincent spent five nights working tirelessly on this game. We have to agree: It is very cool!