Hi garbo73, I also installed recently FC5 64 bit, and it's really promising.
About repositories, if you have checked /etc/yum.conf, you'll notice that the only available repositories for now are the ones for development. The $release variable right now points to 4.92. As Fedora repositories only contain free software packages you'll not find nor Nvidia or ATI drivers (in my case). Furthermore, other repositories like dries and freshrpms don't have yet repositories for FC5. This means that you have to wait until FC5 is released then you can configure your repositories.
One more thing, FC5 uses Xorg 7.0, so you need an Nvidia driver for this version. No ATI driver yet.
About your USB mouse, it's possible that FC5 didn't recognized well, check the result of:
and also check the device that was assignated to your mouse in the directory /dev. With this info you can edit the file /etc/X11/xorg.conf, and put the right values in the mouse section.