While not stated as Open Source (yet) like the SL2 OS video player. it is still a already packaged and free to use and adjust Silverlight 2.O (beta 2) video player you can use in your site for your videos and that like the SL2 OS video player it now support Time Markers.
This is called the MinoPlayer and now it is in version 1.2. it comes from a very good Italian Silverlight and WPF developer and it has chosen its video player as the first app to release code for everyone to use.
Unlike the SL2 OS video player that goes for the Vimeo/Flickr player look. the MinoPlayer goes for the familiar look of the YouTube design and recreates it perfectly.
I found the MinoPlayer really easy to use and if you want to see a live version of it. it is also in the MinoPlayer page for anyone to have a look at it.
