Today I noticed that Flash 10 was released for Linux. The version is 10.0.12.36.
Still no 64bit version but, the the long standing bug of having flash menus appear behind other content has been finally fixed (assuming you have Firefox 3.0.2 or newer).
On systems that use RPM you can run:
$ sudo rpm -Uvh http://fpdownload.macromedia.com/get/flashplayer/current/flash-plugin-10.0.12.36-release.i386.rpm
Or if you have Adobe yum repo installed (recommended), just do a:
$ sudo yum update flash-plugin
Be sure to read the Flash 10 Tips for important info on using Flash 10.