I'm using F19 on a UEFI box, and except for the fact that I had to use:
grub2-mkconfig -o /boot/efi/EFI/fedora/grub.cfg
The theme is working. Just one hitch, I'm getting an error with grub looking for /EFI/fedora/locale/en.gmo, just before the grub screen appears. Is anyone else seeing this error?
Edit: A quick edit before they archive F19, in case anyone is seeing the error. The Arch forums have this for a solution: cp /usr/share/locale/en_US/LC_MESSAGES/mit-krb5.mo /boot/grub/locale/en.gmo. It obviously has to be edited for Fedora, but, it's good start. Haven't tried it yet. OK, now you can archive.