I'd rather not start using FireFox or Chrome, unless there is some compelling reason.
But blocking auto-play (of all kinds) is starting to look like a compelling reason.
When I go to a website and start to hear audio spam,
I can turn it off in the location bar (to the right of the URL),
or I can mute the whole machine ... but this gets old quick.
Sometimes turning off JavaScript can help, but that also is tiresome.
I like the ClickToPlugin approach ... turing content on optionally in context,
just wary of 3rd party software which often breaks with each new Safari.