I'm in Las Vegas, attending the Mix 07 Conference. Two weeks ago, Microsoft announced Silverlight (a cross-platform, cross-browser run-time). At the keynote, Ray Ozzie announced that .NET technology is being brought to Silverlight. Silverlight now gives you a new choice for developing rich applications in the language of your choice.
Scott Guthrie described the media experiences that Silverlight enables . . .
. . . and Neil Hunt from Netflix and Darin Brown of Avenue A/Razorfish demo'd an application that they've created using Silverlight: the Netflix Movie Player, that runs on both the PC and the MAC -- built in only three weeks.
You can get more information about Silverlight at http://www.silverlight.net. Take a look at the Silverlight documentation and be sure to check out out the Quick Starts and start creating Silverlight applications today!