Viewing Jackass 2.5, a terrible disappointment and waste of your time actually gave me a chance to review long-form content on the Silverlight platform.
The interface was nothing fancy... and definitely typical amongst the Flash crowd. Controls were responsive... but bah.
THE VIDEO...
... started fairly quickly, and looked great... and then it started...
... Silverlight can't hold sync with audio and video to save its life. I tried pausing the video several times and it maintained the drift. Terrible. By the end of the movie drift was almost 5 seconds off.
I haven't known this to be a particular issue with Windows Media. I tend to work with a different video streaming solution. :-) It looks better than Flash, but I'm partial to what we do at Move... especially when it comes to long-form content.