HTML5 video fragmentation is showing it's head. Firefox will not support h.264, chrome will likely not support it either.
Meaning flash will be the best solution. Googles video format will be open so other browsers could adopt it. I know nothing about the codec yet. H.264 is my go to codec for device encoding and youtube right now.
Chrome already supports H264, they won't remove it in favour of WebM. Firefox needs to suck it up and support H264 too. Cheap bastards.