i updated a few days ago without a hitch:
Code:
sudo rpm --import https://fedoraproject.org/static/246110C1.txt
sudo yum update yum
sudo yum --releasever=20 distro-sync
sudo shutdown -r now
uname -a -m -p
Linux mom 3.11.10-301.fc20.x86_64 #1 SMP Thu Dec 5 14:01:17 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux