With extensions you might be able to force certain sites to use a different user agent string instead of leaving it set all the time. Or, like the YouTube extension I have, it just forces that specific site to use HTML5 video tags. I've found the YouTube preference itself always gets hosed after a while.

But yeah Tom, I totally a agree. You want shameful? TUAW - The Unofficial Apple Weblog was *constantly* posting stories with a flash video as the main image - super annoying. And utterly short-sighted of them.