I'm still somewhat confused by web-video with HTML5, specifically how do the users install the video codecs and does HTML5 enable a seamless experience for inst

I'm still somewhat confused by web-video with HTML5, specifically how do the users install the video codecs and does HTML5 enable a seamless experience for installing them similar to the express install of the Adobe Player? Alot more goes into streaming video to the web than just the choice of front-end plugin (Or lack thereof), rebuilding out your encoding/editing systems to handle other codec's could get very expensive, for example our small studio has poured over 6 figures into setting up just the editing rooms and encoding servers.