just to be fair, you can do the same in Chrome's prefs.
It's different though. Chrome lets you Click to Flash, but that only affects half the YouTube videos available now because the OTHER half use HTML5 which ends up playing no matter what. And extensions are useless because they don't always load before the tab so you end up having to manually stop all your tabs.
Safari however will not load anything in the tab until I click it. Much like the option in Firefox. I haven't done too much testing, but I will. Currently I had a tab open with a YouTube video that uses HTML5 (Which means it would get through Click to Flash since it's not using Flash.) and it did not start the plugin until I focused the tab.
That makes me happy. Plus Safari is so much better on my processor and battery. Who would have thought. Now, if only they could fix the rest of its problems, like the current state of the extension market.
That's a feature? I always assumed it a was a bug in Safari.
Battery saver. Do you really want every single tab with an auto-playing video or audio file or even a Flash-based advertisement starting up when you open your browser sucking up your battery and processor even though you haven't even touched it yet? I know I wouldn't. I think it's an option though so if you DO want it to start stuff, I guess you could have it do it.
I'm gonna do some testing. Hopefully it's not a fluke.
Edit: Yep. Works like a charm. Except it exposes Google's stupid oversight of having YouTube tabs display the PLAYING icon by default and hiding it when you pause. Which means if a tab is loaded in the background or otherwise the video is not actually loaded yet, it still says it is. Google, fix that shit. It's a simple oversight. Don't leave it forever. Sheesh.