The next Adobe Flash Player release finally re-syncs the 64-bit build with the Flash updates in the mainline code available to 32-bit users. This is the first public beta release of the Adobe Flash Player 11 that offers both 32-bit and 64-bit binaries to Linux users, along with 64-bit binaries for Microsoft Windows and Mac OS X users.
Adobe Flash Player 11 Beta drives innovation for amazing, breathtaking digital experiences with brand-new features, including Stage 3D, HD surround sound, H.264/AVC software encoding and 64-bit support.
Download : http://labs.adobe.com/downloads/flashplayer11.html
The final version of Flash Player 11 will be released before the end of 2011.
For setup see a former post : http://debian-bits-and-snips.blogspot.com/2011/02/setup-flash-non-debian-way.html
When using flashplugin-nonfree just do the following as root :
Resolving download.macromedia.com... 22.214.171.124
Connecting to download.macromedia.com|126.96.36.199|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 7044701 (6.7M) [application/x-gzip]
Saving to: “./flashplayer11_b1_install_lin_64_071311.tar.gz”
Restart iceweasel and check version at about:plugins