Just in time for YouTube to get Adsensed and the Joost launch (promising a set-top), Adobe Media Player is now in prerelease public beta. AMP attempts to bring the best of both the broadcast television and web video worlds to your desktop. Not sure about that, but ads and metrics are features for producers as noted in previous posts; see Online players again (especially the Deeje Cooley video) and Adobe adds H.264 support to Flash; AMP delayed.
I'm still wondering Will Adobe address Joost Copycats? Will AMP keep up with the smaller innovators (UI, etc...) and will CS3 users benefit from integration? More at Mashable's Adobe’s New Media Player Launches with Several Partners.
Update: Adobe's Edge newsletter go deeper with Adobe Media Player: A new way to deliver high-quality content.
If you want more on Silverlight vs. Flash check out the many thoughts at JD on EP.