I tried out the Alpha on Archlinux. It was working great with much more stability and lesser CPU usage, but unfortunately, it crashes Firefox for me, when i open Gmail. So, i have gone back to Flash 10 x86 + Nspluginwrapper for now. Will keep trying it as and when they release newer versions.

Download Flash 10 x64 Alpha.

Edit: The plugin works perfectly for me now! Not crashing the browser anymore

Changelog:

New audio/video options

• H.264/HE-AAC codec support
  Flash Player 9 Update 3 includes H.264 video and High Efficiency AAC (HE-AAC) audio codec support that opens up a broad ecosystem and selection of standards-based video — up to HD quality — that developers can leverage in their applications. Supporting a subset of MPEG-4 Part 12 (container) and Part 10 (H.264), including baseline, main and high profiles, Flash Player can play back existing MP4, M4A, MOV, MP4V, 3GP and 3G2 content.

Improved Performance

• Multi-core support
  Speed the rendering of vectors, bitmaps, filters and video, including true 1080p video, with new multi-core support that takes advantage of up to 4 CPUs.
• Hardware scaling
  Improve the performance and quality of full-screen video through the use of hardware scaling.
• Multi-threaded video decoding
  The VP6 video codec now runs in a separate thread on multi-core systems, enabling true 1080p video. In addition, the responsiveness and decode blockiness of the VP6 codec is improved with this change.
• Image scaling
  A new algorithm for scaling bitmap images enhances the quality and rendering performance of downscaled images.
• Flash Player cache
  The Flash Player cache enables common components, such as the Flex Framework, to be cached locally and then used by any SWF from any domain. Use of the Flash Player cache can significantly reduce SWF file sizes and speed application download times.
• Flash Media Server buffering
  The stream buffer is maintained while a stream is paused.

Universal Reach

• Full screen mode for Linux
  Full screen mode with hardware scaling is now supported in Linux.
• Accessibility support for the plugin
  Flash Player 9 update 3 adds support for Microsoft’s Active Accessibility (MSAA) API to the plugin, enabling consistent support across plugin-based and Internet Explorer browsers.
• Mac Os X Leopard support
  Flash Player 9 update 3 now supports the Mac OS X Leopard operating system.

Fixed in this version:

• On Linux, modal dialogs displayed by Flash Player stay in front of browser windows but do not prevent interaction with the browser as they should. (191331)
• On Windows Vista, Internet Explorer 7 Protected Mode may prompt users with security warnings when attempting to view Flash content after installing the Flash Player 9 (9.0.45.0) ActiveX control. Security warnings may also appear for users who choose to install the Google Toolbar from the Flash Player Download Center on adobe.com as part of the player installation process. This was fixed in an Internet Explorer update in June 2007.
• On certain SUSE 9.2 installations using the standalone player only, trying to Open a browser from the standalone player with SeaMonkey open will cause the player to hang. (193383)
• On Linux, networking operations in the standalone player are currently slow. (193158)
• On Linux, when the mouse is hovering over Flash content, keyboard input is not sent to the browser. (194265)
• Full-screen mode is not supported in the Opera Browser on Macintosh systems. (189140)
• Full-screen mode is now supported on Linux.
• Invoking document.write(..) method of JavaScript using ExternalInterface or FSCommand hangs Safari on next page load. This issue has been reported to Apple. (167996)
• The Mozilla Plugin Finder Service will not install Flash Player 9.0.20.0 on Intel-based Macs using double-byte language modes. Users may either install from the Adobe Player Download Center or use the Plugin Finder Service in non-double-byte language modes. (180719)
• The plugin version of Flash Player does not fire flash.events.Event.RENDER when wmode is set as transparent. (198515)
• Full-screen can be used when wmode is set (202290)
• Passing large amounts of XML through External Interface is significantly faster (206828)
• ExternalInterface now works with HTML objects that contain dots within the object name (199614)

Here is the list of security updates.