Odd, video on the site works for me on Firefox (25.0.1 on OS X), and we're actually using mediaelement.js which is listed on the page you link to. What OS/version of Firefox are you using?
I don't think it's an argument against Dixon's point, but I found this funny because I remember being so impressed with demo of Dropbox at the time. I remember knowing nothing about who Drew was, seeing this on HN: http://news.ycombinator.com/item?id=8863
and thinking something along the lines of, "that's brilliant, I hope he gets funded so I can use it."
That has not been my experience. While no one here would correct you, I've never heard it pronounced otherwise except when discussing the pronunciation (which comes up a lot).
He has been kind enough to share about his setup quite a lot about lately. In fact, looks like it's on the HN homepage right now: http://news.ycombinator.com/item?id=872301
It's better at load balancing. For example it handles app servers that have gone down more gracefully. Also it generates an awesome stats page that gives you way more info about what's going on than you can get from Nginx.
Having Nginx in front is a lot more flexible that just having HAProxy listen on port 80. For example, it can serve static files and do redirects both of which don't need to pass through the whole load balanced stack.
They could use Nginx -> HAProxy -> Nginx(w/ passenger), but the Apache version feels slightly more mature (e.g. it has some config options that the Nginx version lacks) and it's likely they were already using it before the Nginx version came out.
It was certainly the first thing that came to mind for me. After seeing the URL, I was pretty disappointed not to find a magical nonthreatening pansexual spokesthing on the actual page.
https://news.ycombinator.com/newsguidelines.html