Interesting news: Mac Rumors: Adobe Annouces H.264 Support in Flash
The reason I find this interesting is that most of the popular video sites have settled on Flash-based players as their standard user interface. From my experimentation, H.264 provides the best size/quality ratio that I’ve seen for screencasting, at least among codecs that are broadly supported. So, the addition of H.264 to Flash means that the Flash player can now be a good platform for lossy-encoded screencasts.
It’s worth noting that TechSmith’s Camtasia product already produces high-quality SWF Flash movies. Those movies are actually lossless and look fantastic, but they are bigger than a comparable H.264 movie.