"in most cases, Flash video streaming is still more expensive for content owners to deliver, especially for those with a lot of traffic" (full post and comments)
Could Silverlight seriously push aside Flash as the main format for more advanced web applications and experiments? With javascript apps eating away at the other end of the market, losing the video/animation focus could seriously dampen the way forward.
Several media companies are already promoting Silverlight as a Mac/Unix option for their exsisting WMV streaming, thereby helping spread the installed base and user awareness. And solutions like the JW makes it even easier to play around.
Short term? No worries... long term? Netscape, Real Networks and Wordperfect anyone?