silverlight is the recent and trendy product from microsoft as it includes lot of features like videostraming,3D features ,animation as you have in flash.Its very difficult to release a second product and get a chance as the market is already crowded with adobe's flash and video player.But Microsoft is now successful in video streaming with some real user experience.There is a real evidence that CBSSports.com streamed more than 11 million hours of live audio and video during the tournament.NBCOlympics also used Silverlight to stream the 2010 Winter Olympics.
Earlier it was blamed that most of the silverlight sample animations was achieved by adobe flash and not by Silverlight.Many were under the impression that high end animations can only be developed with Flash and not at all possible with Silverlight.
But Microsoft today proves that all kind animations with 3D effect can be developed with Silverlight.Microsoft has released 4 versions of Silverlight in two years time frame.Each version has its own improvements and they also provide many kind of controls to build applications and also many new animation and 3D features.
Recently apple has not provided the support for Adobe Flash in ipad and hence Microsoft is planning have talks with Apple to build some Silverlight features in iPad.
Silverlight in any way, shape or form will never be on any apple product.