Oh, odd. Are you manually opted into the "HTML5 YouTube" version (is that still even an option or just the default for everybody now)? I had to manually "click to enable Flash plugin" to watch their I/O stream a few weeks ago in Chrome.

And, last I checked, Chrome doesn't support HTTP Live Streaming, so if you are using Chrome and getting live video without a pulgin, I'm not sure how it works?

Extra note: Chrome on Android does support, but Chrome-the-desktop-browser does not support HTTP Live Streaming. Computers are awful.