While in Kuala Lumpur on a one day layover before flying back to Sydney. I went a little bit nuts buying Kingston 512GB USB sticks from street vendors for 10MR( Malaysian Ringits) (About 3$ Australian). The USB Keys you can buy in Australia are generally from 4 – 64GB so 512GB is appreciably bigger.
So I just plugged one into my Fedora 21 box and I get.
So the fix
yum install exfat-utils fuse-exfat
Once you install the above you can access the USB-key from the default Gnome Shell File Manager