Whether or not HLS is supported by Chrome is quite confusing. I'm not surprised they blocked it at a User Agent level (which Google does all the time for their services, Reverse Image Search & Maps being good examples).
While Chrome has supported HLS for a WebM backend for some time now, documentation on their support for HLS with an MP4 backend is unclear. It seems to work now as of Chrome 26, but that wasn't always the case. It also works fine on Android devices past 3.2 because of Google TV.
Seriously, that was a little absurd. Why exactly does Apple want to limit its audience by only allowing people using Safari on OSX to watch it? I doubt all the markets are so saturated that every potential iPhone, Macbook, and Mac Pro customer is already on OS X.
If I didn't happen to have a Macbook as a work PC for the summer, I'd have missed the Macbook Air announcement. But god, do I want one.
It's not about limiting the audience. HTTP Live Streaming is just a better technology. Watching the keynote it was blatantly obvious. I have more outright pauses in the average Youtube video than an HTTP Live Stream. It required some rapid and noticeable quality changes but I would much prefer that over the video simply dropping out entirely.
Most just choose not to. That's not Apple's fault, nor is it a reason to fall back to a worse technology that degrades the experience for all watching to help out those on other platforms.
For the record, it wasn't at all limited to "Safari on OS X". Any device or program that properly implements HTTP Live Streaming could easily view the keynote. Apple listed Safari on OS X, the Apple TV, iPod touch, iPhone and iPad as all being verified, but other devices supported it too.
