safari is basically html 5 viewable right now. Most other browsers are also about 60-70 percent compliant. I expect to see these sites cropping up pretty rapidly as time goes on. That date is the compliance standard. But just like HD cable, I think browsers will be much more compliant within the next 2-3 years.
Here is a link with the spiel
http://www.findmebyip.com/litmus/