First of all, I love the NBCOlympics.com site as a great supplement to TV coverage. And it is working very well!
An observation about the Silverlight plugin...anything that requires the user to "install a viewer" is bad these days, because that's exactly the terminology the bad guys use to convince unknowledgable users to run their "Paris Hilton Viewer", or whatever.
Now that some millions of users have a beta version of Silverlight installed, how about maintaining the plugin(s) over Windows Update? This would be better than running into sites where "you need to install a newer version of Silverlight to view this content"
and training them to click on every banner requesting a newer version of Silverlight. The next thing we'll see is malware spewing spam sites requiring an "upgraded Silverlight" plugin to view the "Breaking MSNBC news".
Now that the Olympics have opened, the site is working well! Congratulations on pulling this off. I experimented with some live feeds - they work well, but a cool feature to add would be PVR-like capability of Pause and Instant-replay for live feeds
- with a typical buffer size of 30 minutes.