OK, well, when I first used Fedora I made the same mistake. The default installation loaded a PAE kernel instead of the regular kernel. So when I installed kmod-nvidia it also pulled in a regular kernel. For your install you probably would have had to load up kmod-nvidia-PAE. What you will have to do to clean up the installation is remove the kernel that came in with the kmod-nvidia driver and reset everything using the old kernel. OR. If it is a new installation, just do a reinstall. The choice is up to you. Since I made the same mistake, I can help you fix it. If this is what you want to do, let me know if you see the grub screen when you are booting up, so we can stop the boot from going into gnome and go directly into terminal.
We can also use the live cd to do the repair. But if you can stop the boot at grub, it might be easier because we can just boot into init 3 (by adding 3 to the kernel line) and work from there.
A default Fedora install sets grub to a timeout of zero so that's why I'm asking if you can see it while booting up.

I am moving this thread to the fedora section because it has to do more with fedora's package management functions than drivers themself.

Thanks mfillpot, it really does belong in Fedora.

@win2tank Fedora, as I said before, sets the timer on grub to zero, so, it's hard to catch. Experiment by hitting escape occasionally while it is booting up and see if you can catch grub. If you hit it at the right spot, we can work on it from there. Since we are going back and forth on the forum, I'll try and tell you some things in advance, in case we don't catch each other here at the same time.

If escape works and you can catch grub, press "e" when it appears and add a "3" (without quotes) to the kernel line so we can boot up into init 3, which will leave you at a terminal screen with a prompt.
If you can't catch grub with escape, you will need a LiveCD of Fedora, or, actually almost any other Linux distro. Let me know what you have and we'll go from there.

I'm first trying to get a copy of your grub.conf so I can see what kernels are installed and at the same time I'll help you fix grub so it shows up during boot.

If escape does work and you get to a prompt type in:

su -c "cat /boot/grub/grub.conf"

I need the output from that command to get us started.

I'll leave it at that for now, let me know how you make out.

Good news, you didn't install the wrong type of kernel, you just installed a newer kernel. Nothing to do here, but, lets make sure you can see grub the next time you boot up.

su -c "nano /boot/grub/grub.conf" will open up that file for you.

Change timeout=0 to timeout=3 , and
put a hash mark in from of hiddenmenu (make it #hiddenmenu)

Then hitting ctrl-x and then "y" will save the file for you.

You should be back to a prompt at this point, so lets see what you have.

Let me see the output of
dir /etc/modprobe.d/
and
dir /etc/X11/