According to an official press release from Adobe , blog entries from RIA Platform Evangelist Ryan Stewart , Flash Player Engineer Tinic Uro , Flash Player Product Manager Emmy Huang , blogger Richard McManus  and others, later today Adobe  will be posting an updated beta of Flash Player 9 on http://labs.adobe.com  that adds support for several of the profiles of industry standard H.264 video and HE-AAC audio CODECs along with some other great enhancements! The final version is scheduled to ship later this fall. The new formats are also going to be supported in an upcoming release of Flash Media Server. Truly awesome news for Flash Platform developers, media developers, and producers. The options for video formats in Flash just exploded with a huge bang. Very good news for a variety of projects that revolve or rely on the Flash Platform.
Not only are the new CODECs and containers supported, but they build on the already announced hardware accelerated, multi-core enhanced, full screen video playback that was introduced in the previous Flash 9 beta 3 on labs.adobe.com. Now you’ll be able to view any H.264 encoded video including MP4 and MOV in full screen with hardware acceleration right in Flash.
One key item to note, is that you if you have a project that still needs to target ActionScript 2.0, you can still use these new features in your projects as the API’s haven’t changed, just the type of contents that are supported. As long as the visitor to your site or consumer of your content has the updated Flash 9 player installed (which you can very easily determine and upgrade for them via the Express Install API  in Flash) then you are going to be able to deliver a great experience. I’m assuming that looking at the properties of the System.capabilities object might also return additional info about H.264, etc. similar to the way it returns info about MP3 capabilities. you could potentially use that or simply evaluate the player version, and you’ll be able to intelligently determine what formats the player currently consuming your content is capable of loading and displaying.
As always, Tinic Uro has a ton of great details and insight  into the nitty-gritty of the new enhancements and features, including the exact profiles of H.264 that are supported, and other pertinent details. As is typical of his posts, not only does he delve into the new features, and why/how certain decisions were made on the new fetures, but also some side effects of implementation. In particular one item he makes note of is that when implementing portions of the AAC audio codec, they needed to resample everything up to 44.1khz, so he was also able to fix the long-standning issue with certain sampling rates of mp3’s resulting in accelerated playback or the “chipmunk effect”. As he mentions, this has been around for years and is finally fixed – thank you Tinic! I first ran into this years ago when pulling in dynamically generated mp3’s – I’m glad thats finally fixed! There is far more info in Tinics post about the profiles and various items, metadata, etc. that make up the enhancements that have been announced.
I’m super excited about this release as I’ve been working on a number of video and Flash Media Server projects recently and each of them will potentially benefit from this new release and path that Adobe has put the Flash Player on.
I’m definitely placing an order for an Elgato turbo.264 H.264 Video Encoder Accelerator  right now!
I’ll update this entry with more info once the official bits are posted at http://labs.adobe.com/technologies/flashplayer9  later today.The following is an FAQ about the capabilities that Emmy Huang, Flash Player Product Manager put together about the new Flash 9 Player beta “MovieStar” release.
What is H.264?
H.264 is the next-generation video compression technology in the MPEG-4 standard, also known as MPEG-4 Part 10 (ISO/IEC 14496-10). H.264 delivers excellent video quality across the entire bandwidth spectrum – from 3G (Mobile phones) to HD (Broadcast) and everything in between. H.264 is now mandatory for the HD-DVD and Blu-ray specifications (the two formats for high-definition DVDs) and ratified in the latest versions of the DVB (Digital Video Broadcasters) and 3GPP (3rd Generation Partnership Project) standards.
What is HE-AAC?
A: AAC is standard audio format defined in the MPEG-4 video standard, and is also the default audio format of the Apple iPod, and the standard audio format for Sony’s PlayStation 3. Flash Player supports HE-AAC v2. HE-AAC v2 is an extension of AAC that uses Spectral Band Replication (SBR) and Parametric Stereo (PS) techniques to increase coding efficiency at low bitrates.
What audio and video standards does Flash Player 9 Update 3 implement?
Flash Player will support subsets of the MPEG-4 standards and the 3GPP timed text format as defined by the following:
* ISO/IEC 14496-3 – Audio AAC: AAC Main, AAC LC, SBR
* ISO/IEC 14496-10 – Video AVC: Base (BP), Main (MP), High (HiP). All levels are supported.
* ISO/IEC 14496-12 – Container: 1 audio and 1 video
* 3GPP TS 26.245 – Timed text
Does H.264 in Flash Player support alpha channel?
No. Our first implementation does not support alpha channels using H.264, but we plan to implement this feature in the next major release.
Will I be able to multiplex H.264 video and AAC audio into the current FLV container format?
Adobe encourages customers to use the new MPEG-4-based file format. The new file format is designed to work with the features of these codecs.
Will I be able to put On2 VP6 streams into the new MPEG-4-based file format?
The Flash Player 9 beta will not playback On2 VP6 encoded video in the new file format.
Can I play back the same H.264 video files that I use on my iPod?
Yes, Flash Player can playback any H.264/AAC files that play on the iPod provided they are not protected by FairPlay DRM.
Will Flash Player 9 Update 3 support non-FLV files/extensions?
Yes, with this update, Flash Player will also support MPEG-4 standard container files that contain video and audio data encoded using H.264/AAC, including MP4, M4V, M4A, MOV, Mp4v, 3gp, 3g2.
What are the minimum system requirements for viewing H.264-based content in Flash Player?
The minimum system requirements for viewing H264-based content will be similar to other media players supporting H264 in the market today. There will be a full list of system requirements and their associated playback capabilities posted on adobe.com when Flash player 9 is released.
Will H.264 be included in AIR? When will it appear in the AIR Labs releases?
Yes, H.264 will be included in AIR 1.0. It is expected to be available to AIR developers in a public beta on Adobe Labs later this year.
Will the Adobe Flash Media Server support H.264 content?
Yes, the next version of Flash Media Server will support streaming of H.264 content and AAC content – both live and on demand. More details on this will be released later in the year.
Will there be an updated FLV File Format Specification? When will it be available?
Yes, Adobe plans to make the updated specification available after the final release. The specification will describe the new MPEG-4-based file format container supported by Adobe Flash Player.
When will Flash Player 9 Update 3 ship?
Flash player 9 Update 3 is expected to be available from the Adobe Flash Player Download Center later this Fall.
What parts of the H.264 license are included when I buy Adobe Products?
The end user license to the Adobe Flash Player allows users to playback H.264 content for your own non-commercial use. Commercial use of the Flash Player to decode H.264 video may require a separate license.
What are H.264’s licensing terms?
Licensing terms for H.264 are available at www.mpegla.com and www.vialicensing.com.
What is MPEG LA?
MPEG LA is in the business of offering users access under one license to essential patents for standards-based technologies owned by many patent holders. MPEG LA provides these licenses as a convenience to the market in order to save users the time and expense of negotiating individual licenses with multiple patent owners and the resulting payment of many separate royalties. The licenses offered by MPEG LA include patents that are essential to implementation of H.264.
When does MPEG LA require payment of a use fee or royalty, and do I need my own license for H.264 ?
MPEG-LA has a number of categories where parties may be required to obtain a license and pay a royalty. Categories include: AVC Products, Title-By-Title Video, Subscription AVC Video, and Internet Broadcast AVC video, among others. Most categories apply to commercial uses and implementations, but some apply more broadly. Whether the license applies to your use; the applicable royalty; and the threshold for application of the royalty varies for each category. You will need to contact MPEG LA or review the license terms to determine if your use falls within a particular category. MPEG LA has posted a FAQ (http://www.mpegla.com/avc/avc-faq.cf m) and has a Q&A Department (firstname.lastname@example.org ) for those questions not answered by the FAQ.