This is still emerging tech but it's stabilizing rapidly — both Firefox and Chrome play back at 60fps on a MacBook Air. On a sub-$1K laptop it's noticeably slower because things are disabled due to Intel HD 3000 driver bugs but those bugs are now getting a lot more attention since they're so visible. I'd expect the situation to be a lot more viable in a year or two, so now seems to be a good time to start learning the technology and thinking about how to use it.