Youtube has already converted at least 2/3 of their old videos into WebM, and all the new ones are converted to WebM as well. I hope Google makes the WebM player the default on all browsers supporting it, and leave Flash fall-back for the others, once they have all of them converted (early next year?). I figure by then they should fix all the remaining issues with it, too (no fullscreen mode for 1080p video, etc)

I think it's the only way to make video on the web not be patent encumbered. They need to take a stand and push for it, with their own services. Nobody else is going to do it for them. They should adopt this Apple-like strategy with WebM, like Apple did against Flash (and it turned out to be the right one). Google only really embraced Flash on Android to spite Apple anyway, not because it was the right strategy or path to take.