You might be interested to know that Adobe, the creator of Flash, has updated its Internet player to support H.264 video.
Adobe said in a statement:
[The player enables] the delivery of HD television quality and premium audio content through the ubiquitous Adobe Flash Player.”
For those not in the know, H.264 video is a compression standard also known as MPEG-4 Part 10, or AVG (for Advanced Video Coding). You can read more at Wikipedia, but to quote a snippet:
The intent of the H.264/AVC project was to create a standard capable of providing good video quality at substantially lower bit rates than previous standards (e.g. half or less the bit rate of MPEG-2, H.263, or MPEG-4 Part 2), without increasing the complexity of design so much that it would be impractical or excessively expensive to implement.
Separately, Adobe has also announced that the upcoming Adobe Flash Media Server 3 release will include H.264 as well as AAC+ audio codec support. A new encrypted protocol will serve to protect streamed content.
At the moment, H.264 achieves the "best-ever compression efficiency for a broad range of applications" for those who already implement it in QuickTime. You can read more about H.264 from Apple's site as well.