YouTube has slowly but surely been expanding the availability of WebM in their HTML 5 open video beta, but uploaders have so far had no control over whether their videos would be available in a free format. Videos deemed popular enough by Google would be made available in WebM, but other than that, only videos which happened to be HD (720p or greater) would definitely be viewable in WebM. Scaling up the resolution of a video was simply not an acceptable workaround. Back in June, i posted to the WebM Discussion list suggesting that all videos uploaded in WebM be made available in WebM, regardless of resolution or popularity.
Things got pushed back a few times, but now, as announced in a new thread, all new videos uploaded to YouTube in WebM will be available in WebM, finally giving uploaders the ability to make sure their videos can be viewed in a free format using HTML5. This is an important step, and hopefully it will serve to increase the use of free formats for video offline as well. Towards that end, perhaps they can also make sure videos uploaded in other free formats like Ogg Theora are viewable in WebM too.
If you're a YouTuber, make sure your your videos don't use annotations,don't display ads, and are uploaded in WebM to ensure they will be viewable in without Flash or h.264. Additionally, it may take a while after the video has reportedly finished processing before the WebM version is available.