Just wanted to document here for others trying to do the same.
First, create the virtual machine, and make sure to give it at least 64MB of Video Memory, and select Enable 3D Acceleration in the Display section of the VM’s settings.
Then, install Fedora 16 (I used the Live GNOME Media). Second, disable SELINUX by editing the /etc/selinux/config file and setting SELINUX=disabled. Reboot the VM.
Then, drop into a terminal and run sudo yum –y update kernel, once completed, reboot. After reboot go back to a terminal and run sudo yum –y install kernel-devel kernel-headers dkms gcc gcc-c+
After this is completed, you can then select Install Guest Additions from the Devices menu in VirtualBox and run sudo ./VBoxLinuxAdditions.run in a terminal at the Install directory.
Finally, reboot the VM again, and you should have fully working Guest Additions, and a fully functional GNOME Shell environment.