I can't see Steve Ballmer and Steve Jobs stopping the production lines off the next Office and the nex iPad just to adopt the new format in their browsers because "some engineers at Google decided to figure out if there was a way to" save some Kbs.
Once video become the main source of traffic, which flows trough DSL lines, image size become almost irrelevant. Who cares about a 42 or 62 Kb. image if it's just a thumb of a 16 Mb. .flv video?