Flash 11 is in public beta, and seems to address some of the issues the old 64 bit flash plugin was having with new versions of glibc (if you're not familiar and have some time on your hands, see RHBZ 638477.)
The "installer" is basically a tree of pre-built binaries, desktop files, and icons, with no makefile or install script. I'd much prefer to keep track of these files and have an easy way to uninstall them later, so I came up with a quick and dirty spec file for the 64-bit release. I'm not redistributing the RPMs, but you can build them for yourself with my spec file at:
Hopefully someone finds it helpful. And if you're running 32 bit Fedora, it should be trivial to modify the spec to grab the 32 bit tarball.
This spec file is provided AS-IS, with no warranty or support.