Image via WikipediaIt was only a matter of time. YouTube can now be viewed in most modern browsers WITHOUT FLASH.
HTML 5 adds several new technologies to a developers toolbelt, one of the biggest is the new embed video tags. This makes Plugins like Flash, for video useless, it slows down your browsing and just plain makes watching vids on slower computers boring regardless of how nice the videos are.
To Try out YouTube without flash player go to YouTube's TestTube. Another thing to try on there is streaming and Feather.