How about not running videos by default _AT ALL_?
"All videos should either be muted by default _or_ should require a deliberate user action to start playing." Can we make that "or" an "AND"?
I know third-party software exists to block Flash and other extensions, but wouldn't it be wonderful if all adverts waited for you to tell them they could download and run? I can't tell you how many websites, and more importantly products, have totally turned my off by making me sit there while all their video advertisements loaded and played. Not all of us have the most brand-spanking new computers or FIOS network connections and we are not happy having to sit on our hands while a website loads a ton of content that we do not care to see. Worse, after all the videos load, we then have to put up with our computers being bogged down trying to play the videos, especially when you get a site with multiple video ads all running simultaneously.
A lot of corporate good will would be garnered if companies simply made their ads wait for us to tell them when / if they can run. Who would you rather buy from: someone in the mall who presents a pleasant storefront and is perfectly willing to answer your questions if you come up and ask, or the girl who, without your consent maces you with the latest fragrance, or worse, the creepy guy who tries to rub your head with a scratcher thingie that looks like it was made in a junk yard and has been scraped on who-knows how many diseased scalps that day.
(Yes, the latter was based on personal experience and the aforementioned thingie was nearly placed in a location where the sun does not shine, but I felt the malware analogy was relevant.)