Fedora 21 note: grub2 prompt
Fedora 21 installed on my main laptop ( Thinkpad, formerly Fedora 20.) Came up at a GRUB2 prompt instead of booting normally. Used this to fix:
grub2-mkconfig -o /boot/grub/grub.cfg
grub2-install --target=x86_64-efi
(Found on Gentoo Forums. Appreciating the Gentoo scene right now.) I'm still not noticing a lot of differences yet, but at least I won't be showing up at SCALE this year without the shiny new thing.