Thanks for posting this presentation.
Bad news: Sound for this slideshow won't play in Silverlight 3.0.50106.0 (from silverlight.net) in IE 8.0.6001.1870 and FF 3.6, Win XP SP3 + all updates, AMD Sempron 1.8GHz. I don't think it's a CPU issue, because other videos do play with sound, such as this one uploaded by Jossie on the same day (Sept. 23, 2009): http://channel9.msdn.com/posts/Jossie/Connected-Information-Security-Framework-Core-Components/ and http://channel9.msdn.com/posts/Jossie/Technical-Preview-for-CATNET-20/
Good news, workaround: copying the URL from the embed HTML ( < /> icon) and pasting it into Windows Media Player 11 "Open URL", the video+audio streams perfectly:
The trouble?: WMP11 says the audio codec is: "Windows Media Audio 10 Professional, 128 kbps, 44 kHz, 2 channel 24 bit 2-pass VBR". 24 bits seems like overkill for a voiceover, and Silverlight 3.0 won't play it. (Or is it a container problem?)
Suggestion: In future, encode audio for WMA 9 and/or 16 bit for maximum backward compatibility.