Guys, the answer seems a lot simpler than we though, at least for my case.
Apparently there is a compatibility issue between the nvidia drivers and the default nouveau driver used by the fbcon on Fedora 12 and others similar, preventing the Nvidia proprietary driver to work even after it is properly installed with the -k $(uname -r).
There are 2 ways of dealing with it:
1. change the default initrd:
mv /boot/initramfs-$(uname -r).img /boot/initramfs-$(uname -r)-nouveau.img
dracut /boot/initramfs-$(uname -r).img $(uname -r)
2. keep the original initrd, but disable the nouveau driver:
edit /etc/grub.conf and add the following to the end of the line(s) starting with 'kernel':
#2 worked flawlessly for me, the complete reference can be found on the following links:
Good luck !