Mozilla’s support of Ogg likely to help Flash? http://bit.ly/d3sFQ3

Working on the assumption that Flash will be provided as a fall-back position for desktop browsers, Mozilla will keep Flash alive because it’s unlikely that Ogg codecs will dominate. This is particularly likely now that Microsoft have announced that IE 9 will support HTML5′s <video> tag with H.264 video.

The other driver is the mobile space where H.264 is hardware accelerated but Ogg is very unlikely to be. Mozilla does not have much of a mobile business for Firefox so they are ignoring this growing and likely dominant outlet.